I played the campaign for MW3 and BF3 I like them both.

I also have played both Multi Players and here is my opinion

If MW3 Creators got together with BF3 Creators there would be an epic game so awesome. We could only whisper the name.

I like the graphics on MW3 But I like that you can kill the cover on BF3.
I like the vehicles on BF3 and I hate on MW3 that there is a perfectly awesome looking jeep or tank sitting there and you cant use it.

I like the maps on BF3 that are bigger and that you have to use actual team work.. This would be great on MW3 but sadly its not the case.. You have the same lonewolves doing the same shit..

Just My .02 and all