I personally hate the arsenal spec in pvp, tried it a couple of times and i got bored of it very fast. But i do have to say that neither a nerf nor a buff is needed. Ofcourse you can put a cooldown in Tracer Missile but that would screw us a bit in pve, we can't stack 5 heat signatures quickly meaning our heartseeker missiles will not do that much damage. If a cooldown is the only option there have to be another series of changes that would still make us competative in damage compared to other classes.

bumping for the greater good