I'm considering adding a 28mm lens to my Leica M. Usually I go from 21 to 35mm. Over the years I've used a number of Leica 28mm, as well as the Canon 25 and several Voigtlander 28mm f3.5. 28mm is not a focal length i'd use often, and given the cost of the Color-Skopar these days, I thought I'd consider the Canon. Also it might be a plus to have the lower contrast of the Canon vis-a-vis the Color-Skopar. Any comments on the Canon 28mm screw mounts from users, current or past?