First, in case you missed it, PGI has stated that two issues are currently making LRMs to powerful in the game. Details of that can be seen at: http://mwomercs.com/...93#entry2369593 So don't go ranting about how LRMs are OP right now, the current state is temporary.
What LRMS were like yesteryear (December 2012 to Februrary 2012)
Back in December of last year, not long after MWO went into open beta, PGI finished a series of bug fixes, adjustments, and feature additions that put LRMs into a fairly stable state for several months. In this state, LRM missiles had a fairly shallow flight path, traveled at 100 m/s, and did 1.8 damage per missile. They were viable, and useful, but really depended on TAG and/or Artemis to be able to do significant damage, and mechs could take cover from them behind anything slightly taller than their mech. Even though damage was at a high 1.8 per missile, it was mitigated by the wide missile spread; even with TAG and Artemis not all your missiles would necessarily hit a target. Personally I liked the state they were in during this time, but some still complained they were OP, while others stated that ECM ruined them and they were worthless.
What LRMS were like for a few days (March 2013)
In March of these year PGI put through a patch that fixed a bug with splash damage not working right. This introduced a new bug/feature that made splash damage work even less right and do massive additive damage. This caused LRM missiles, which were still at 1.8 damage per missile, to do huge damage to small and medium mechs, and increased damage even to larger mechs. In this state the missiles were totally broken and a single salvo of LRMs could kill many mechs.
What LRMs were like yesterday (April and May 2013)
PGI "fixed" the above issues with a Hotfix in late March. This hotfix pushed LRM damage down to .7 per missile and reduced splash damage radius. No changes were made to the missile spread, speed, or flight path. After these changes, LRMS because very ineffective and little used. A player could shoot 30 LRM missiles with TAG+Artemis, and only manage to do 10-15 unfocused damage. I don't know why LRMs were simply not reverted to their pre-splash "fix" state; I guess splash damage changes were a genie out of a bottle at this point.
What LRMs are like now (May 21st patch)
This weeks patch saw several major changes to LRMS. First, damage was increased from .7 to .9 per missile (still far short of the old 1.8 number). Second, speed was increased from 100 m/s to 120 m/s. Third, missile spread was decreased a little overall, so the missiles are packed more tightly and more are likely to hit. Finally, the flight trajectory was changed a little to give them a steeper up and down angle.
That last change is bugged however. The steeper flight angle is only supposed to work if someone else is spotting the target for you, so you can shoot targets behind cover if they are scouted for you. But that steep angle is working even if you are self spotting, so if a target runs behind cover and you maintain lock long enough, your missiles will dive right in.
Another problem is that missiles have a tighter grouping now, but splash damage still happens, causing smaller mechs to take a lot of center torso damage.
These two issues combine to make LRMs overly effective, especially on smaller mechs and in situations where mechs only have short cover.
What LRMs will be like tomorrow (Next patch or hotfix)
Ok, here is the big one. What will LRMs be like after they are "fixed"? Who the hell knows. The big problem here is splash damage. It is not clear what they are going to actually do to it to fix the problem. Splash damage + tight missile grouping = death to small mechs. This is because missiles that hit the arms and side torso also push splash damage to the center torso, so smaller mechs take a disproportionate amount of CT damage. And if they just remove splash damage (which they really don't seem to want to do)? If you do that, then the .9 damage on LRM missiles becomes to low. In short, it is very hard to say what state LRMs will actually be in after fixes. They may still be OP, or they may go back to being little used.
TLDR;
LRM balance is a very complex issue dealing with missile grouping, tracking strength, speed, damage, splash damage, and target size. Do not expect them to be balanced after the upcoming patch/hotfix, I think it will take even more time after that.
Edited by 80Bit, 23 May 2013 - 06:47 AM.