I have not had the chance to use the 7D other than a few dozen family pictures in room light. I did use the camera's flash as a driver with another flash as a slave. Pictures came out great with bright colors and very sharp. The response of the camera is very quick and the AF grouping is great.
Fast / Accurate Auto-Focus; Fast Shutter Speed; Good Image Quality; High ISO Performance; Large Clear LCD; Quiet
None; Too early to tell