Turn based, Elite or Warrior.
I'd be up to a small-middleish battle with limited awesomeness (no M1A2SEP APS or T-90 for example).
I don't care much about the rest, aslong as it's not purely city (bad fps), I'm fine with any terrain.
Disclaimer: I have no experience in CM MP so I cannot say how much of an opponent I can be, I'd like to change that (obviously )