I played Battlefield 3 for the first time in the last couple of days.
hated it. Much prefered Battlefield 2 and Bad Company 1/2 for online. I hate the way the guns sway and have so much inertia, very hard to be precise with your aim, I'm no god when it comes to FPS but I can generally hold my own and even trying to get accustomed to the way the guns handle made me want to smash the TV. Not only that but I found the menu customisation options for weapons and loadouts to be such a pain in the ass. Half the time I'd accidentally select a shotgun from the quick-select box when actually trying to choose my spawn point.
IN GENERAL, I would play and pick Battlefield over Call of Duty any day but unfortunately I just can't get on with BF3 and so for MW3 vs BF3 I pick MW3 :sadbanana
Although I still think BF2(+packs), BF:BC1/2 and even BF:P4F are better than any Call of Duty..