I don't mind the shotgun spammers too much, I generally stay away from clusterfuck hallway free for all's and pick em off from a distance. It's comical how many idiots in warzone are content with spawning in a crowded area to try and just rack up kills, I do wish GG would look into giving greater XP bonuses for doing the missions, or even being in the general vicinity of missions to keep people from doing this for example if I escort my buddy in SR I should also get a point for helping deliver him safely IMO. Same with C&H as well.
Nothing beats a nice 8 vs. 8 game though, play with some cool people and it's a thing of beauty.