Mw2 is a horrible game, they took Call of duty 4 which was a decent solid multiplayer experience and added everything their fanbase wanted.
Yeah, some of the improvements were good, such as new scopes, customisable killstreaks, and mosh pit, but some were bad like being able to knife from 30 feet away even without commando while taking a full clip of ammo without slowing down, akimbo shotguns, painkillers, and removing old school free for all. Personaly, I think Modern warfare 1 is better because of its simplicity and more realistic controls.