An actual test of my camera (as opposed to all the other diddling around I have posted here) and the Redrock M2.
The adapter performs well as far as color and feel go. I was using a Nikon 50mm f/1.8 on the front of it. Had heard a few bad things (and many good things) about this lens, so I was hesitant, but it was fairly sharp. There's some vignetting around the right edge in particular though it's not visible in every shot. I rushed through adjusting the alignment, so that's probably why. The bokeh is very, very nice on this adapter in particular which is why I went with it over the Letus (that, and the lack of spinning ground glass in the Letus)
Didn't have a 1st AC obviously, or the shots would have been in focus more. My neighbor Fuyuki and his garden were kind enough to volunteer as test subjects. :-)