I've been playing MW2 recently but not a lot. I have had an easier time knifing and using the RPD as my best run and gun, I haven't encountered any cheaters but I do encounter a lot of boosters and it give me joy to kill them and wait a second and kill them again due to tactical insertion. All I can say is when you find a cheeter just leave the lobby and try a different game type. It seems like there are more cheeters in team based games then free for all but I might be mistaken :/ BUT on the off chance I am correct, it's better to deal with boosters then cheaters :D