It's nothing like COD4, it uses a different engine and it's made by a different developer. The only similarity is that both games have guns, killstreaks and perks. It's like saying BC2 is exactly the same as the original Battlefield, and if I were to say that you would probably call me a Call of Duty fanboy. Perhaps the issue here is that I play games like this on a console, and Battlefield is really a PC game, rather than a drop in drop out console game.