I disagree with some of the points above with the APS-C big advantage being mostly about price.
When I bought my 7D, I was choosing between it and the 5DII. I chose the 7D over the 5DII because I felt, for me, it was a better "camera" overall. Since then I have added a 5DII to my kit (actually paid less for it than my 7D during a Canon refurb sale).
I don't have any EF-s lenses as I have multiple bodies in my kit.
I chose the 7D for the better Ai Servo focus system, pop-up speedlite commander (which I use all the time), viewfinder grid/ level, custom functions, better video integration...
I won't disagree that the 5DII has better RAW image quality/ high ISO overall, because it does, but that is the only thing it does better that the 7D. I use my 5dII personally more.
Professionally I actually use my 7D way more than my 5DII- I shoot a lot of product photography for packaging/ marketing/ PR. The majority of my professional photography (I'm a toy/ CE designer) is done with a 100mm macro and 2 430EXII Speedlites. This kit is super small and quick with just a 7D. I don't use my 7D at high ISO levels so I don't care about that "issue", and my photos don't print at 100%, so again you don't see all that "noise" EVER. I also like the crop the 7D does to my photo in camera (I'm not shooting 1:1 macro) since I want a little more DOF while filling as much of the frame as possible.
I also will take my 7D to the park as a "sports" camera to capture my 2yr old daughter. She is super fast