I've held off on getting this because none of my friends have it. I hear the same thing Weaste says, it's all about who you roll with. If you have a bunch of people only caring about their K/D spread, then you're screwed. I've also read about some lag issues, but I don't know how they compare to most other games.
SOCOM can be less of a pain in the ass, and because the teams are generally smaller, it is easier to find those that would cooperate tactically. And a new SOCOM should be coming out later this year.