I'm only lvl 9, so I still don't have many options for perks, weapons and such. I'm using Marathon, Lightweight, and the one that increases melee distance. I basically run around like a crazy person and SMG or knife anyone I come across. So far it's pretty fun, but I'm really surprised how high I rank in many matches (I sucked badly at COD4). I'm not sure if the "pro" players just haven't separated themselves from the pack yet, or if there's a lower skill-ceiling in this game. Maybe the better players are steering clear of Ground War?