I know this is also probably not what you want to hear, but I don't think either is a very good match for your 7D. It of course depends on what you are looking for in a new lens, but if it is light gathering power, I would suggest the EF-S 17-55/2.8 IS instead. Both lighter and cheaper than the EF 24-70/2.8L, but just as good, if not better, IQ. Also a more useful focal range, IMHO. 24mm is not really wide enough on APS-C (try it on your current lens). No weather sealing though, if that's a big deal for you.