I think, that in general, LRMs are quite balanced.
There is a situation that arises in most games right now. Two trenches form around terrain features (hills, houses, bunkers etc) that are approximately 1000m +/- 200m apart. Those trenches are sometimes (rightly so) broken up by LTs. If no LT is rapping the trenchers, they happily lob LRMs.
But those LRM boats are actually quite inefficient in those situations. Often i sit waiting at 900-m for a poptard to jump up, light up as a christmas tree (radar active, since he uses LRMs), just to get my ERPPC/Guass in his face. His return punch (LRMs) is no concern. I just backup and hide behind my trench. And he just doesn't seem to get that his volleys are inefficient.
If some mech lumbers between those trenches without support and without AMS then he gets rapped by LRMs.... but i guess thats what one deserves for an unsound choice.
One may find that trenches are kind of boring (and they can be). But they are broken by LTs, sometimes by brawlers ganging op to flank, sometime by one side killing a lot of enemy trenchers and breaking through.
At least we have more strategy going on than the simply 'grab mech, jump into the fray anywhere on the map, kill, die... repeat' that was so dominant in the beginning of the mods open beta.