In most cases I would say the same think as every one else glass, glass, and more glass. However, after looking at your gear list may be you should try a 7D. If you want to shoot some fast moving subjects. cause I know how unfast the 5D's are. There is a time and a place for a fast body. It will make your glass so much faster. borrow someone's 1D and try it on your glass. It may have been something your have been missing the whole time. I hope you just take this as my 2 cents only.