I sold my 7D after I had the 5D mkiii for a month, I simply stopped using it. The reason I bought the 7D was for focus and general shooting speed. I used it every time I thought the focus system of the 5D mkII wouldn't cut it. The 7D is a great camera, but doesn't match the iq of the 5D mkiii at any setting, or the focus system for that matter.
Great isn't it? I have attached another image that I could never even have dreamed of with my 40d. It was shot with a 100-400L, 1/400 sec @ f/7.1, with an ISO of 10,000! And the amazing thing is that this shot is cropped down to less than 1.5 MP. Sure there is noise but wow, no way with a 40d or a 7d.