MW2 is terrible online...when I am playing with my friends, 60% of the time, one of us is dropped from the matchmaking (then we have to back out and try to find out where he went). Also, there are plenty of moments in which the game should chose a new host and does not. There are times it tries to chose a new host, fails, and then boots back to the lobby (leaving everyone with no progression). The most fail thing is their matchmaking system which can literally place a rank 1 with a rank 70 (both parties going in independently), I have seen it. It is highly addicting and if they could rework a lot of these issues, this would be a highly polished a stable game like Halo 3. Instead, the multiplayer is just good and it loses its chance at being the greatest FPS ever.