ok here is my opinion , with this a have a k/d of 2.75 and +- 80k exp a hour
* Kill-streak setup : care package , attack helicopter , dogs (don't use chopper or gunship they always shot down before u get a kil)
* Class Setup : AK74u+grip+rapid fire (scavenger , warlord , marathon). rapid fire and grip is a really good combination , like stopping power in mw2
* Flank Routes in a map : i always run fast as possible to the enemy spawn (thanks marathon
) and go to places where they don't expect you
* Game modes TDM , headquarters , demoltion