I ended up going in another direction. Well, actually two directions. First, it looks like the Sigma 35mm is the better option, so that's now on the list. Lots of rave reviews on B&H and elsewhere. Unfortunately, it looks like you pay for that extra value. I may also be jumping on the Canon bandwagon on Black Friday, so for now, I'm just going to wait until I've confirmed which compatibility I would need until then.