I love the battlefield series, the graphics are amazing and so is the gameplay. I think battlefield is going to overall be a better game than mw3 but mw3 is definitely going to have a larger online fan base
I doubt it will be the Call of Duty killer come the time when Modern Warfare 3 is released in around two weeks time. Also, I heard it's good but the EA servers for it are terrible. Don't know what to believe but the server issue wouldn't surprise me, after all, it is EA.