In general I like the idea of ECM, it can give a good balance to LRMs and even SSRMs, but I am not sure that what we have seen is the best fit.
Two quick ideas to limit the effectiveness ECM, but still have a great deal of value
1) Could it be Ammo based, the antithesis of NARC? You then shoot friendlies with ECM, there is a time limit before it wares off, and it holds many of its current properties for single mech. You would then need extra Ammo and to be aware of its status.
2) Could each individual ECM unit have limited ability? I could see this in two different ways. One being that a single ECM unit has fixed number of mechs (or tonnage) it could mask. You could add extra units to extra effects. The second could being reduced functionality with more mech (or tonnage) with in its area of effect (This would seem to be a nightmare to actually code and make happen)
Edited by Hop per, 07 December 2012 - 09:56 AM.