I've only done some quick testing of my copy of this lens to be sure the Fotodiox Nikon to Eos adapter works properly, which it does. I can tell you that the 50mm f2 is easy to focus without an af confirm chip, and it's really sharp at f2. In fact, I couldn't see any difference between f2 and f4 in sharpness with my handheld shots. Many photographers consider this lens a sleeper. Upon first look I tend to agree. I can't wait to test it in good light. I also noticed it handles very well at close focus distances. I think it will be a great macro lens with a bellows or tubes.

Update: Bokeh fringe testing confirms this would be a very good macro lens. This lens exhibits excellent control over bokeh fringing with little color shift. The only noticeable artifact is a loss in contrast which is not a detriment to the photo.