I really liked my first copy of Canon's 28mm f2.8 (version 2 in this test), and for some reason I now seem to have 3 of them - 1 from each batch that Canon made. These pictures are quick tests of each of them (on a tripod, Live View focused on the Ilford film boxes and shot with self timer) along with 3 from a Leica 28 Summicron at the end of the folder.

Bottom line... Any of these little lenses work OK at 5.6. The Version 2 lens had been cleaned awhile back by Horst. I'm curious if the Version 3 (which I seem to like the best) might be even better after a CLA.