Starting with speed: The Locust has a max engine rating of 190 while the Flea has a max rating of 170. This gives the Locust a speed of 153 kph to the Flea at 137 kph. Skills can shift these values pushing the Flea up to 150 kph and the Locust to around 170 kph. For 1 ton the Flea 17, 20, & FA can use MASC to reach 170 kph as well, though because acceleration with MASC is instant the Flea actually gains in the short term and loses in the long term. The instant acceleration also allows the Flea to evade or 'jink' like a Shadow Cat, though being smaller this actually works even better. With heatsinks to reach the 10 HS minimum the max engine for the Locust weighs 9 tons, and the max engine in the Flea weighs 8 tons. So with MASC they weigh the same. The Flea though will use more space due to having at least one less internal heatsink compared to the Locust. This is the reason some builds work much better with SHS to save space.
Weapons and equipment? The Locust typically runs 1-6 Energy Hardpoints, 0-4 Ballistics, 0-4 Missile Hardpoints. The Flea runs 1-7 Energy, 0-8 Ballistics, and 0-2 Missiles. You may notice these look very similar, the exception being the max of 8 ballistics compared to 4 on the Locust. The missiles are so hard to use as a 20-tonner that the reduction in missile hard points doesn't really hurt them. For equipment, both have access to ECM and Stealth armor in one variant. I'll compare them variant to variant a bit later. It should be noted the Flea does have high weapon mounts that are often above the the cockpit.
Overall impression: Very similar to the Locust. Very slightly shorter, very slightly slower, very similar play style, slightly more weapons tonnage. If you like the Locust, try the Flea. While it won't replace the Locust, it's every bit as good and all the variants tend to pack a kick, even if some are a bit niche.
Now for the variants:
The Flea 15 comes with 5 energy hardpoints and 2 ballistics. It lacks stock EE, FF, or DHS. The CT energy hard point is fairly low, but the other hard points in the side torsos and arms are nicely high mounted. It's a bit like the Locust 3V, but with much better energy hardpoints though it will run much hotter than the 3V.
The Flea 17 has 7 energy hardpoints making this the energy boat of the Fleas. It is also one of the variants that has access to MASC. It comes with EE, saving you some money as you won't need to buy it. Fitting 7 MLs or SPLs will be impossible if you want a 170 rated engine, basically max armor, and MASC. All of those together comes to 21 tons. More likely you'll downgrade at least some lasers to ERSLs or simply run 6 lasers instead of the max of 7. The FLE-17 is very similar to the Locust 1E.
The Flea 19 has 8 Ballistics and 1 Energy Hardpoint. It comes stock with EE. This is the Piranha for the IS. It's closest IS match is the Locust 1V, which only has half the ballistics slots. It does feel a bit under gunned with only a single energy weapon (most likely a single SPL, ML, or ERML). I ran mine with a single ERML and 8 LMGs with 2.5 tons of ammo. I have actually managed to run out of ammo almost every match. On the up side with the new SHS buff, you can run SHS without overheating.
The Flea 20 has 5 Energy Hardpoints making it another energy boat. Stock it comes with Stealth Armor, EE, DHS, MASC, and has ECM. This makes it very much like the Locust Pirate's Bane. Or more specifically a Pirate's Bane with a Locust 3M set of hardpoints. I personally dropped the stealth armor for LFF and used 4 MLs.
The Flea Fire Ant has 6 Ballistics and 3 Energy Hardpoints. Stock includes EE and MASC. This is another Locust 3V competitor and is arguably superior with more energy and ballistics options as well as MASC. Fitting all that in and having sufficient ammo is the hard part. All it's weapon mounts are above cockpit level and SHS is a valid option so this variant fills an interesting niche.
Finally the Romeo 5000 which has 5 Energy and 2 Missile hardpoints. It comes with stock EE and DHS. It can run a pair of SRM4s or even a pair of SRM6s (with 1 ton of ammo so only 10 shots), but fitting missiles in along with other weapons is very hard. If you wanted to be very strange you could even run a pair of LRM5s. However, lacking MASC makes it less interesting than it could be. This will compare closely with the Locust 1M if you use the missile hardpoints, if you don't it is much like the Locust 3M.
Comparisons:
Locust: You've read down to here, so you've seen the comparison the entire time. The Locust is generally faster over time, but is starting to show it's age a bit by having less hardpoints than the Flea in general.
Osiris/Wolfhound/Firestarter: All larger, heavier energy boats that are at least as heavily armed and less fragile than the Flea. All of them are also slower, though not hugely so if given a large enough engine.
Piranha: The clan 20 ton mech. The 2 and 3 are very much like the Flea 17. Meanwhile the 1, A, and Cipher fall in line with the Flea 19 and FA. As usual for clan mechs though, the Piranha takes advantage of weapons that weigh less for similar performance. This means more guns, higher alphas, more equipment, and more ammo. Though without MASC it doesn't have quite the burst speed of the MASC equipped models of the Flea. I went up against several Piranha's and it's just not an equal fight.
Final Thoughts:
The Flea so makes me want to see a Locust IIC in MWO, with that extra 5 tons to play with and weapon hard points like the Flea has... Oh and clan weight weapons.
The 19 is by far the most swing of any of the variants. If your team can open the enemy for you, you can tear bits off the enemy all day. If not, your one laser isn't getting the job done. With clan MGs weighing half what the IS ones do, I just don't think it's worth it.
Edited by Shadey99, 23 June 2018 - 05:35 AM.