I bought my 7D back in December last year. I had problems with the AF and was told (like most people get told) that it was user error. Ignoring the fact that I read manuals on nearly any new piece of equipment I buy and that I'm not exactly a newbie when it comes to DSLRs, I gave the camera the benefit of the doubt.
I watched all three of those hour long lecture videos, the short videos on Canon's site and whenever time permitted, I would go out and shoot in varying conditions utilising as many AF modes as I could.
The fact is, after nearly a year with the 7D, I have no confidence in it. I can accept not getting a shot if my shutter is too low or I'm not holding the camera steady or any other error caused by me. But when conditions are perfect and I still get a shot that's out of focus, well, it's hard to keep blaming myself. I'm talking even something as simple as a portrait using a tripod. The only way I know I'll get the shot in focus is if I shoot in Live View which, as you can appreciate, isn't always ideal.
I spoke with Canon Australia today about the issues I've been having. As I was describing the arbitrary out of focus shots, he stopped me and implied that he has dealt with this issue before. He went on to say that, "if you were happy with the shots you were getting on your 400D and your using the same set of lenses, then it sounds like the body is definitely the culprit." I was instructed to bring in the body with all my lenses to the service centre tomorrow for them to investigate. I'm not entirely sure what to expect as I've never had to take a camera back before.
I guess the reason for this thread is to let 7D owners know, that yes, the AF is a different beast on the 7D and it does take some getting use to. But that sometimes, the problem really is with the camera.
I still love the 7D; the features are what made me choose it the begin with. I just can't wait to start shooting with confidence again.