I have both the 7D and the 5D2, I'll give you some advice. Take that 5D2 back ASAP and get the 7D.
The 5D2's sensor is better than the 7D for sure, but for the very great majority of people you'll see very little difference. The low light ISO performance of the 5D is also a couple stops better than the 7D, but thats where the good stuff stops for the 5D
At 3 frames a second the 5D2 is slooooooooooooooow... too slow to get any good action.
It has 9 AF points... which is a total scam. Only ONE (the center one) is accurate enough to be used for any reason. This center point is pretty useless in low light as well.
The AF system as a whole is abysmal. The single greatest weakness of the entire unit, which cripples it when taking pictures of moving objects is the AF "system" (and i use system very loosely)
There are two important areas the 5D2 excels, the full frame sensor, and its low light ISO performance. BOTH are worth nothing when 6 out of 10 shots are out of focus.
The only two areas of photography where this camera is any good is portraits and landscapes. The two areas of photography where you have a completely immobile subject. If it moves, the 5D2 will miss it.
Thats not to say the camera can't be used. Lots of professional wedding photographers use it, but its a mystery to me how they pull it off... manual focus maybe?
The 7D on the other hand is a FANTASTIC camera.
The AF system on it is top notch, even for the age, there are few cameras that can rival it. It has 8 frames per second and every one of them will be sharp and in focus no matter what your subject is. (assuming you are using a lens with a motor fast enough to keep up.)
It does have a crop sensor, which is the only thing on the unit I would change. Its low light high ISO performance is very good. Not quite as good as the 5D2, but you can comfortably shoot 1600, 3200 in a pinch, vs 3200, 6400 in a pinch on the 5D2.
between the two cameras, each has its use. the 5D2 is a portrait / landscape camera and the 7D is an action camera. Thats not to say the 7D doesnt do portraits or landscapes just fine because it does. The same cannot be said about the 5D2.
I'm going to have a half dozen people argue this whole post right away, so I ask this to all you who come to argue:
"Is what I've said about the AF system untrue."
If the answer is no, then you have no argument. Nip it in the bud before it even starts.
The 5D2 takes a beautiful image. But if your forever fighting for focus, wtf good is it.
In my opinion, take the 5D2 back before its too late and get the 7D.
Canon camera, Canon lenses.