Just my opinion! I have the 7D and the 5DMII (2 in fact). I always have the 7D in my camera bag with a 5DMKII. IMO, I think the AF on the 7D is far better and tracking something moving the 7D wins hands down. Anything static, I say is a toss up though the 5D does seem a little better.
Why the 7D & 5DMKII? &d has some features the 5DMKII doesn't have and if I need them, I want to be ready. By the same means, the 5DMKII overall is a better camera, photo quality wise.
BUT ... Personally, I do not think either is a better camera than the other but equally as good as each other in different respects.
I voted 7D because if you shoot motorsports, the 7D is the camera to use. Portraits ... I do give the edge to the 5DMKII however the 7D isn't exactly a slouch at that.
Why not shoot for both? It can only work in your favor. Also nice to have a backup if you need one!