51 replies to this topic

[Fox With A Shotgun]

AMS. The last word in defending yourself against nasty, homing, quickly-multiplying creatures known as missiles. Equip your mech with 1.5 tons of AMS and ammunition, and watch that annoying missile rain disappear!

Disclaimer:
May result in negligible reduction of 'Mech damage output. Ammunition sold separately. 'Mech manufacturers are not responsible for any incidental damage arising from misuse or ill maintenance of provided equipment.

Jokes aside. AMS should not be disregarded in regards to making your mech last longer against missiles. SRM, Streak SRM, LRM - all of these can be shot down by AMS. It costs only a paltry 1.5 tons and 2 critical spaces to have enough protection to defend yourself against up to approximately 220 inbound LRM/SRMs (220-440 damage, or the equivalent of ~6.8-13.6 tons of standard armor), or a sizable amount of SRM/Streak SRM. To make it weight-economical for someone to bring an AMS, it must block at least 48 LRMs or 24 SRMs worth of missiles (equivalent of 1.5 tons of standard armor).

The function of AMS is that it targets a missile, starting at 240m, and fires at it to destroy it. Some testing on this matter has been done before by other members of the community: here is one such video below.

[color=#BBBBBB]https://youtu.be/lHC...k6w0L4LEmctM4wQ[/color]

It appears that one AMS blocks approximately 3 missiles per LRM volley, and approximately 1 to 2 (depending on distance) SRM/SSRM missiles per volley, before modules. A moduled-up AMS will take out approximately 5 LRMs per volley, or 2 to 3 SRM/SSRM missiles per volley. Clan LRMs, being fired in a long ripple, would naturally have more missiles shot down. So what does this mean to you, exactly?

Lights:

What's that, I hear? You, as a light mech, do not want to drop that one medium pulse laser? Oh, alright then. Here's Mr. Streakcrow for you. I'm sure he'll love to be your friend. Isn't that right, Mr. Streakcrow? Wait, where are you going?

....Oh. I guess there's not much of you left.

Yes. That 1.5 tons of AMS, especially with a module, can actually block a pretty sizable portion of inbound missiles. If in a volley of SSRM 6x2, you can drop 3 of them, that is the same as blocking 6 damage from incoming missiles out of a barrage of 24 damage. A potentially life-saving amount, on a light mech where you don't have the armor nor internal structure to absorb that damage well. That being said, you should be careful enough to not run into SSRM boats...

...Which means that on light mechs, this becomes largely situational. AMS is largely wasted on SRM/SSRM due to their high speed and typically large volleys, and you should not be getting rained on by LRMs on a fast light mech played properly. 1.5 tons out of the (heaviest light mech's) 35 is a sizable chunk of firepower, speed, armor or any combination of them, so this pick is situational at best, and wasted in most cases. Not to mention that most aggressive lights that are likely to run into SRM/SSRMs do not have enough tonnage to make allowances for this little tool.

Heavier support lights, like the kitfox with KFX-C right arm or the RVN-3L with an ECM may benefit from AMS however due to their nature of hanging around the body of the team to provide maximum support.

Mediums:

Hello there, Centurion. I'm sure you're feeling pretty safe, behind that shield-arm of yours. Unafraid of the LRM rain, hmm? Prefer to fight in the shade? Well, I'm sure your lance-buddies aren't so keen on getting rained on. Speaking of which, is that your arm? Well, it's not yours any more.

1.5 tons of AMS on a medium mech is likely not as costly as it would be on a light mech, but it is still something. Especially on mechs that like packing heavy STD engines. It is, however, a good pick for mechs that stay around the deathball, or are LRM boats themselves. If you stick around your light mechs in a wolfpack, they would certainly appreciate your anti-missile shield vs LRM, and some SSRM cover never hurts.

With a bit more armor and internal structure than a light mech, medium mechs typically last longer to make proper use of the AMS. When it takes more volleys to drop you, that means your AMS actually does more work.

Consider the case that 10 LRM 10 volleys drop on your head. You block 4 missiles on each volley, meaning you've just blocked 40 damage, leaving you with 60 damage remaining. This 60 damage distributes itself across CT, RT, LT, RA, LA, LL and RL; assuming all of them hit evenly, this is an average of 8.6

Heavies and Assaults:

Are you sure that you do not want an umbrella? No, really. It looks like rain, today, with a chance of dismemberment. Still a no? Your bulging muscles look good, but you're not...oh, I guess it's already started raining. What's that? You want back into the house? I'm sorry, you're already locked out.

Now we're talking. You're a big, bulky target. Slow and lumbering, often with craptons of explosive ammunition and nowhere near enough armor to protect your barn-sized frame. When it rains, you can't get in the shade fast enough, so you end up having to fight in the shade (that the missiles just made for you).

Now really. With 65-75 tons of tonnage, surely you would think that sparing 1.5 tons for an AMS is good insurance, yes? Some heavies even pack 2 AMS hardpoints, for a total of 2 tons. It's enough to block out some LRMs. And if you're never alone (which you should never be alone), all the better, because all your AMS-toting buddies are there to hold up your shield against the rain!

Here's the kicker, however: the more AMS in the area there is, the more missiles get shot down! If one AMS is capable of shooting down 4-5 LRMs on its own, then 4 AMS in one area is capable of blocking 16-20 LRMs in a volley. Enough to neutralise a small LRM boat, or half of a LRM40 catapult, all with no effort on your part. If the whole team was to bring one, then that's protecting against 48-60 LRMs in a volley. Enough to deflect any but the most concentrated barrage of missiles against your team!

TL;DR:

- AMS provides the equivalent of 6.8 to 13.6 tons of armor per ton of ammunition it expends, depending on what it shoots down.
- Each AMS almost completely blocks a LRM 5 volley.
- More AMS in an area means more protection, and helps with providing total immunity to missiles for the team.
- Lights may find it difficult to mount AMS, except for support lights.
- Heavies and Assaults, being the most vulnerable to missiles (and also having the most available tonnage) should almost always mount AMS, unless if short on critical spaces.

Edited by ArcturusWolf, 04 November 2015 - 09:22 PM.

[InspectorG]

Ugh, sorry. AMS is a waste of tonnage better spend on a bigger engine, more cooling, or more guns. AMS only makes a difference if the whole team carries 2 per mech...yeah. Not happening.

They will shoot down a whopping ONE SRM.

Save 3 million Cbills, buy radar Deprivation Module. Weights...zero tons. Not only breaks missile lock but also has a stealth element to it.

Best thing to do is read the forum about the SKILLS needed to save you from the dreaded LRMs. Those skills will make you a better pilot. AMS wont.

Also, with all the ECM mechs running around, you may not even need Radar Dep...though it is an overpowered module.

[Fox With A Shotgun]

InspectorG, on 04 November 2015 - 08:28 PM, said:

Ugh, sorry. AMS is a waste of tonnage better spend on a bigger engine, more cooling, or more guns. AMS only makes a difference if the whole team carries 2 per mech...yeah. Not happening.

They will shoot down a whopping ONE SRM.

Save 3 million Cbills, buy radar Deprivation Module. Weights...zero tons. Not only breaks missile lock but also has a stealth element to it.

Best thing to do is read the forum about the SKILLS needed to save you from the dreaded LRMs. Those skills will make you a better pilot. AMS wont.

Also, with all the ECM mechs running around, you may not even need Radar Dep...though it is an overpowered module.

Well, to be fair - I've seen far too many assaults and heavies get bogged down by missile rain. They benefit most from AMS - it doesn't weigh much, and it does block out a large amount of missiles for them when used en masse. Lights and mediums can effectively break LoS from LRMs to not get hit completely, but the heavies and assaults generally can't. Especially if fired from under 500m.

I agree with you though that for most part, AMS is useless against SRMs. They're very much useful against LRMs at this time, though.

Radar dep isn't only for ECM mechs, though. If you're in an aggressive light, it's useful for stopping that 1.5 seconds of lock after you've broken LoS. Keeps the people chasing after you guessing as to where you've gone.

[jss78]

InspectorG, on 04 November 2015 - 08:28 PM, said:

Ugh, sorry. AMS is a waste of tonnage better spend on a bigger engine, more cooling, or more guns. AMS only makes a difference if the whole team carries 2 per mech...yeah. Not happening.

They will shoot down a whopping ONE SRM.

This part I don't quite get. Why is AMS more useful if more people carry it? That suggests that there's an exponential return, that two AMS shoot down more than twice as many missiles. The best I figure it's a linear return -- two AMS destroy exactly twice as many missiles -- or possibly slightly diminishing return if more AMS's shoot at the missiles than would've been needed to destroy all misiles.

Not arguing for or against AMS, but I like the OP in that he focuses on the correct metric, the number of missiles shot down per tonnage spent on AMS. My gut feeling is that where I play (T3 pug) AMS is so-and-so -- on some wide open maps AMS quite often easily saves its tonnage's worth of armour (either my own or team mates'). But in other maps there's plenty of cover, and in some games there are so few LRM's that AMS hardly activates at all.

Interested to see how things change with the rebalance (ECM nerf, LRM buff).

[Fox With A Shotgun]

jss78, on 04 November 2015 - 08:54 PM, said:

This part I don't quite get. Why is AMS more useful if more people carry it? That suggests that there's an exponential return, that two AMS shoot down more than twice as many missiles. The best I figure it's a linear return -- two AMS destroy exactly twice as many missiles -- or possibly slightly diminishing return if more AMS's shoot at the missiles than would've been needed to destroy all misiles.

It's because the return is actually inversely proportional to the number of LRMs hit. If the idea of AMS is to increase the lifespan of a mech. Consider the following case:

Volley of 20 LRMs, 20 volleys @ 1s apart (i.e. approx 240m distance, or the max range of an AMS):\
0 Mechs carrying AMS: 0 missiles shot down/volley = 20 missiles hitting/volley. 400 missiles hit.
1 Mech carrying AMS: 4 missiles shot down/volley = 16 missiles hitting/volley. 320 missiles hit.
2 Mechs carrying AMS: 8 missiles shot down/volley = 12 missiles hitting/volley. 240 missiles hit.
3 Mechs carrying AMS: 12 missiles shot down/volley = 8 missiles hitting/volley. 160 missiles hit.
4 Mechs.... 16 missiles shot down = 4 missiles hitting, 80 missiles hit in total.
5 Mechs+, all missiles shot down.

At first glance this looks like a linear relationship, which it is if you consider damage reduction. But what it really does is if you consider the original goal of AMS (extending life expectancy under missile rain), the time-to-kill (TTK) increases inversely. If we take the mech to be made of one part, just to simplify things, and it is 320 hp worth of mech, and that the complete barrage of 20x20 LRM is 20 seconds long, which can repeat after 20 seconds:

0 Mechs with AMS = 400 missiles hit = 16 seconds to kill
1 Mech with AMS = 320 missiles hit = 20 seconds to kill
2 Mechs with AMS = 240 missiles hit = 26.67 seconds to kill
3 Mechs with AMS = 160 missiles hit = 40 seconds to kill
4 Mechs with AMS = 80 missiles hit = 80 seconds to kill
5 Mechs with AMS = all missiles shot down = infinity seconds to kill.

This is why the more mechs you have, the more effective AMS is. TTK is inversely proportional to the amount of damage taken per unit time; and if you can reduce that damage taken per unit time closer to zero, you can drive up TTK to stupid high levels.

Also, I messed up my calculations. 1 ton of AMS ammo = 2000 shots. 9 shots of AMS kills 1 LRM, so 1 ton of AMS drops about 220 LRMs.

Edited by ArcturusWolf, 04 November 2015 - 09:19 PM.

[Leone]

I, Leone, approve of this thread. *Stamp*

There are a few things quite as glorious as watching a company of stalkers charge right through a clan defense in CW because every mech on the IS side brought AMS, and the clans brought four missile mechs. Due to the clan ripple fire effect I don't think a single missile ever landed, and this from easily over a hundred tubes firing.

Sure, each assault had to sacrifice a mighty 1.5 tonnes, but really, is that too large a price to pay to know that sometimes, every once and a while, you completely shut down a mech or four without even trying?

~Leone.

[InspectorG]

ArcturusWolf, on 04 November 2015 - 08:39 PM, said:

Well, to be fair - I've seen far too many assaults and heavies get bogged down by missile rain. They benefit most from AMS - it doesn't weigh much, and it does block out a large amount of missiles for them when used en masse. Lights and mediums can effectively break LoS from LRMs to not get hit completely, but the heavies and assaults generally can't. Especially if fired from under 500m.

I agree with you though that for most part, AMS is useless against SRMs. They're very much useful against LRMs at this time, though.

Radar dep isn't only for ECM mechs, though. If you're in an aggressive light, it's useful for stopping that 1.5 seconds of lock after you've broken LoS. Keeps the people chasing after you guessing as to where you've gone.

An Assault that gets bogged by LRMs has positioning issues, not AMS issues. or is getting singles out. If my Dire gets singled out, i rather it be LRMs than Dual Gauss or lazervomit.

I roll Direwolf frequently and i really only get smashed by LRM boats when i am one of the 3 remaining mechs and we are about to lose. AMS will not fix that.

[Fox With A Shotgun]

InspectorG, on 05 November 2015 - 02:36 PM, said:

An Assault that gets bogged by LRMs has positioning issues, not AMS issues. or is getting singles out. If my Dire gets singled out, i rather it be LRMs than Dual Gauss or lazervomit.

I'm not going to dispute positioning is better than AMS in most cases. Nor the fact that dual gauss or laservomit will be more dangerous. But there are always places where you can't effectively take cover from LRMs, which is where AMS forms your secondary line of defense. This helps the team by widening the number of places you can go without getting armor shredded by LRM rain.

Not to mention that from calculations alone, a single ton of AMS ammunition provides equivalent protection to 6.8 tons of standard armor, possibly to other mechs that don't have the tonnage or chassis capacity to do take it. Are you saying that is never worth considering?

InspectorG, on 05 November 2015 - 02:36 PM, said:

I roll Direwolf frequently and i really only get smashed by LRM boats when i am one of the 3 remaining mechs and we are about to lose. AMS will not fix that.

Anecdotal evidence is insufficient. I'm giving general advice here.

Of course if you're one of the last three remaining, massively outnumbered, you're going to die from something else more than LRM. It's far more likely to be PPC/laser by that stage of the match, when most LRM ammunition has been expended and therefore the battles get closer together.

Edited by ArcturusWolf, 05 November 2015 - 02:45 PM.

[InspectorG]

ArcturusWolf, on 05 November 2015 - 02:44 PM, said:

Anecdotal evidence is insufficient. I'm giving general advice here.

But your 'General' advice is very dependent on a niche context: the opponent bringing LRMs which is currently uncommon as well as teammates bringing enough AMS to make it worthwhile.

Its 'generally' better to spend the extra tons on more offense in a game that rewards damage output the most.

That 'Armor' is pointless if no LRMs are present. More Gauss ammo is rarely pointless. More cooling for Lazors ir rarely pointless. A bigger engine is rarely pointless.

Tons of ECM teammates makes AMS redundant, anyhow. Dedicated LuRMers will use TAG and that gives me the spot to place my return fire which they very quickly run from. They dont TAG, i dont get LRMed.

If you KNOW you will be facing lots of LuRMs...sure go ahead. Everyone brings a AMS, ECM, Radar Dep, enemy team will have serious problems. They go to TAG, they eat gaussvomit, they wont want to TAG anymore.

[Acierocolotl]

ArcturusWolf, on 04 November 2015 - 08:15 PM, said:

AMS!

Having personally witnessed parades getting rained on (and perhaps being responsible for arranging the rain), and conversely, also having brought heavy AMS support, I can attest to its effectiveness and why people in the solo queue would forgo this will eternally be beyond me. This may be another matter in a group queue, but I'm not prepared to speculate on that.

InspectorG, on 05 November 2015 - 03:03 PM, said:

Its 'generally' better to spend the extra tons on more offense in a game that rewards damage output the most.

With respect, your argument is sort of ridiculous. The logical extreme of your opinion is that you should entirely forgo armour to maximize your offense. You'll point out you meant "generally", of course, but I think it's best to work in specifics. So let me sketch out a scenario:

An Atlas can carry about 15 tonnes of armour at maximum. That 15 tonnes effectively triples the longevity of any portion of the mech. Now I'm not saying you're advocating peeling all the armour off, but just bear with me: If you were to take those 15 extra tonnes of armour and turn them into extra guns and heatsinks, generously, that's a 30% increase in firepower. It's good for an AC 10 with a few tonnes of ammo. But of course, an Atlas with no armour is not going to do 30% more damage than an armoured Atlas, it's going to do way, way less, maybe even none at all. The armour is purely defensive, but it gives you the chance to fire those guns, and to fire them for longer. So armour--again, a purely defensive thing--is good for your offense.

Presuming LRMs are a non-starter for you, we'll only consider SRMs and Streaks. If those SRMs are fired at half range, and all other things being equal, you're knocking down one SRM per volley. If you're close enough to an ally or they're being fired at long range, that's two per volley, and you've diminished ripple-fired SRM-4s by 50%. That AMS with a tonne of ammo will have greatly neutered an enemy's weapon system, doubling its TTK, or by 50% if it's an SRM-6 build. SRM-2s can just go home.

Granted, there aren't a lot of mechs that would rely only on SRMs to fight you, and many of them will be bringing other weapons as well, but in the case of a brawler Atlas, you can focus on knocking out the inevitable AC-20 and not sweat the missile barrage as much. You probably would have anyway, but now its secondary weapons have way less teeth.

If we're presuming you only stopped ten salvos all ripple-fired at your center torso, that's still basically an extra 20 points of armour over and above what you'd've had normally. And over and above that, any ally close to you also getting pasted with SRMs is enjoying free "armour", thanks to you. And that's basically a free AC 20 shot to the chest you can shrug off, because that armour wasn't peeled off by missiles.

In the odd, weird chance you're never going to face any missiles at all, an AMS is wasted space. But show me a team that doesn't use streaks or SRMs, and I'll show you a team that doesn't win as much as it could.

[Sug]

AMS would be effective if the whole team carried it but not that many people use or have a problem dealing with LRMs. There are better options than AMS.

[InspectorG]

Acierocolotl, on 05 November 2015 - 04:22 PM, said:

This may be another matter in a group queue, but I'm not prepared to speculate on that.

With respect, your argument is sort of ridiculous. The logical extreme of your opinion is that you should entirely forgo armour to maximize your offense. You'll point out you meant "generally", of course, but I think it's best to work in specifics. So let me sketch out a scenario:


If those SRMs are fired at half range, and all other things being equal, you're knocking down one SRM per volley.

In the odd, weird chance you're never going to face any missiles at all, an AMS is wasted space. But show me a team that doesn't use streaks or SRMs, and I'll show you a team that doesn't win as much as it could.

Group is different and some mid-level teams roll with a deck built for LRMing. I dont know of any high level players orienting their team around LRM. THATS clue #1.

Clue #2.
Solo is a random grab bag of opponents.
Generally there is LOTS of ECM, Many Clan mechs who use Lazorvomit/GaussVomit/SRM.
YOU DO NOT KNOW YOUR OPPONENT in SOLO so Generalist Meta builds will be the best choice.
Lazervomit or Gaussvomit > Dual Big Dakka > SRM brawler > about everything else.

So in solo, expect enemies to bring the most efficient means of dealing with changing conditions.

Clue #3.
I have yet to hear ANYONE in Solo Prioritize the enemy Atlas. Atlas is a non issue if you can keep 300m away.

Atlas SRM brawlers are good...at 200m. Problem is they must survive long enough to get there, NASCAR they die just like Dires.

Clue#4
SRMs are only 'good' at HALF their optimal range. @100-150m.
Speed and Positioning > AMS. Simple choice. Radar Dep vs Streaks(and most other things)
AMS will do nothing vs Oxides or any Clan with a big Splat.

Scenario:
SplatCrow has 5ASRM6(common enough opponent). You say "AMS shoots down 1 missile at range", ok we run with that. So SCRO fires in volleys of 2 and 3 at 24 and 36 damage respectively. Say AMS shoots 1 missile per launcher that drops to 20 and 32 damage.

SCRO likely carries lots of ammo. He closes at 150M and fires every 1.5 seconds. He decided to focus your right ST because thats were may big guns are in mechs. For simple round numbers say your RT has 100 armor and 50 structure...He needs 9 seconds to do 156 damage.

Now this assumes he is alone, in Solo, early to mid match he likely has friends and we shall put them at low alphas of 30 damage. SCRO and his 2 friends(who use lazors) do additional 60 damage every 3 seconds. AMS does nothing for that damage.
So with 2 friends you eat @112 damage in 6 seconds. AMS stopped 8 of that.

Whats a better bet?

Spending 3+ tons on minimizing(niche) 8 damage every 1.5 seconds?

OR

Spending 3+ tons on more damage to HURT the enemy BEFORE his weapons get into range?
3+ tons Hurting him trying to get an Ammo explosion?
3+ tons on HURTING his morale?
3+ more tons on better heat efficiency to force him to overheat?
3+ tons spent on a better engine to get out of a bad position/ engine with more agility to twist damage?

???

Ask any players who run Splat build and if they even notice if the enemy has AMS.

Slow Assault? Once they get behind you its over. Positioning > AMS.


Clue#5
I never said "DONT EQUIP ARMOR" rather i said "THAT TONNAGE is better spent elsewhere". Misquote there. Many comp players SHAVE deadside armor to fit more Guns/Ammo/Cooling. Why?


WHY DO THEY DO THAT? Why run LESS armor if big bad LuRMs are all over and SRMs are so powerful???

Know why? Because piloting offsets the need for AMS and Terrain has UNLIMITED armor.
Factor this with the fact that Successful MWO play is build around Pushing a firing line into an enemy in a manner that reduced their return fire(capping the end of their firing line/flanking)

MWO is about inflicting MAX damage FIRST in a concentrated manner on the most valuable target while minimizing or sacrificing a lesser unit of your own. This generates the snowball effect of diminished return firepower from the enemy. They get outnumbered and only very mobile units have a hope of evening the odds if very outnumbered. Hence 3:12 stomps. Notice how many wins you get in a Solo if your team is down 3 and the enemy is full strength. Very rare.

'Concentrated' is the key word and thats why the good players talk of how convergence, not LRMs, 'breaks' the game. LRMs are not a focused weapon, have too much travel time, and thus are considered sub-optimal/bad.


Your arguments from 'Specifics' ignores the general Metagame in MWO which is: Do Most CONCENTRATED Damage First on the enemy's most valued unit, Spread or evade incoming damage.

Thats it. Building away from the above is either experimentation, ignorance, or fun.

[Chados]

I like an AMS whenever I can spare the tonnage. I have it on almost all my IS mechs but the two Clan mechs I own don't have enough spare tonnage.

Best? The Jester. Two AMS and a ton and a half of ammo. Still have four LL, and it's very hard for most Clan LRMs to seriously harm me unless there are many of them and I don't have cover close to mitigate.

I've seen two cLRM10 salvos from me...in a TBR...get eaten by mass AMS on the other side. It can be very effective and cause LRMers to have to close up to get anything through the shield.

[SethAbercromby]

The above arguments is why this game can be so boring at times. Meta nonsense taking anecdotal or highly specific evidence to extreme levels to prove their assumed superiority. Whenever I hear people say 'generalist Gaussvomit' I just laugh and cry, especially when I see a high-competitive team upload their matches and I just see both sides tripping over each other's feet because, and I know this might come as a shock, only so many 'Mechs can do the exact same approach at one time.

LRMs are not a primary source of damage, but can result in significant amounts of additive damage. They are a perfect counter to choke point control on a majority of maps, easily doubling or even tripling the amounts of 'Mechs firing at one target. Heck, most Meta designs can easily be tweaked to bring an LRM10 or 5 with one or one half ton of ammo respectively and still laservomit half day long.

[P]

ams is good only to a point,
also good against organized LRM boats
lots of folks think lrm boats are for noobs
but in the proper hands of organized tryhards and know-it-how
ams is a need.
but in common pugs drop

[VitriolicViolet]

The way i see it, if a mech has more than one AMS slot then you should almost always take AMS.

With 2 or more you alone block a large portion of LRM fire especially if you stay near the team. I have a Jester, Crab 27, BK6KNT and take dual AMS with 2 tons of ammo on each. Admittedly half the time i end the match with more than 1 ton of ammo, but the other half it runs out before the end. I consider it invaluble on the mechs i run it on.

[DrnkJawa]

Well most of my mechs started using AMS again and depending on the situation it either helps me take less damage or if more people bring them they create a nice umbrella that drives lrm boaters mad.

[Fox With A Shotgun]

DrnkJawa, on 08 November 2015 - 02:32 PM, said:

Well most of my mechs started using AMS again and depending on the situation it either helps me take less damage or if more people bring them they create a nice umbrella that drives lrm boaters mad.

No AMS:



Everyone brings AMS:

[InspectorG]

[Kurvi]

I think that in general, the answer is "it depends". As such, I would suggest AMS is cheap enough that the best way to decide if AMS is good for you is to simply try it out. If you find that your AMS ammo regularly runs out before the end of the match then yes, it's probably helping. If you are a ninja supreme and your "hide in shadows" ability is so good that your ammo tends to get blown up before being used then probably not.

Yes, this is not an accurate measure but even if you just check your final match score averages (or whatever you are trying to optimize for), that would be the way to go.