They're just different experiences. MW is more "fun" if you want to jump into games and shoot people in the face. The killstreaks and all that jazz are just that: fun.

BF3 is much more of a battle sim. You aren't gonna be sprinting around the map runnin'and'gunnin... It's more strategic and soooooo much more fun when playing with friends in your squad. I just played last night with Roc and Perm, and I had a blast. Most fun I ever had with BF.

I told myself I was going to switch over to BF3 and not get MW3... but I picked it up today and am installing it now. I am stoked to play. I just want to shoot some peeps in the face!!! lol