OK now this was interesting. Indoors, night, compact fluorescent lighting, took 34 snaps with a 24 1.4L II, all shot wide open at 1.4, aimed at subjects all over the room and 33 were 100% in focus! And the one that was off was not off by much! I've never had a hit rate that high under that scenario before. A wide lens wide open is a tricky test for AF. My 5D2 had been the best Canon I'd tried at that sort of thing before and I think it probably missed 1 in 5 shots.