I've had the 24-105 for about a year and a half now. It came as the kit lens for my 5D Mk III. My copy is a very good one, tack sharp and quite fast, as far as I seem to notice. 3 months ago I bought the 24-70 II. It is an outstanding lens, as far as AF response and sharpness are concerned. I think it's better than the 24-105. That being said, is it possible that the 24-105 can still be useful? If I keep it, and don't sell it, to what uses, if any, can the 24-105 be put? Is there anything that I can do with the 24-105 that I can't do with the 24-70 II?!