Different from MW2. Character models are def much less bulky. I think it uses the same core engine that Call of Duty 4 used.
I'm excited. It's a relief to hear that Treyarch is inventing instead of piggy back riding IW(R.I.P.).
The training mode looks good. At first, you think "Oh who cares, I wont play it" But man theres so many times when I get put on a team in an objective mode, and my teammates are just incompetent to the objective. Hopefully that training mode nudges them and tells them they should be doing something, when they are not.