I am not surprised people are starting to hate MW 2, it has become too popular, all popular games receive this backlash, which does annoy me a little actually
MW 2 is a very different game, it is very very fast paced, whereas there is more strategy to Battlefield, and I actually found it a bit empty in the game I played in the beta. A vehicle based online mode is obviously going to make a very different experience to one without vehicles, but having vehicles does not make it better. The WaW games with tanks sucked