I avoid ECCM unless I really need it. Missile Racks already eats a lot of OP, to the point that it is an automatic S-mod choice if the ship will rely on missiles.
@ Aramoro: About "Whaaaat", in earlier releases, MIRVs had, I think, seven submunitions, for a total of 3500 damage per missile. They also split into a significantly tighter cluster. During some of those older releases, I guess around 0.65, they also regenerated slowly. (MIRV was more like an upgraded Pilum, when Pilums were overpowered with Missile Spec. 10, instead of an upgraded Harpoon.) Weaknesses of old MIRVs was the whole swarm was easily stuffed by flak. If the defender had flak cannons, they were effectively immune to MIRVs. Also, the splitting was fast and tight, and ships mobile enough could easily dodge the swarm of sub-munitions. Ships were faster back then too because of stronger skills and hullmods (Augmented Drive Field used to be Augmented Engines, and it could stack with Unstable Injector... at first, and the penalties were easier flameouts or longer repairs, not reduced shot range.)
Also, back then, there were only two large missiles: Hurricane MIRV and Cyclone Reaper. Also, some ships had different mounts.