I've had 3-4 copies of these lenses over the years and this is one of two I have found to be the sharpest. (There was not much variation).

I'm keeping one and letting this one go. It's been modified to bring up 35mm frame lines on your M body and unless the subject is very close, is actually a pretty accurate representation of what you get.

It's really great lens, a little soft around the edges wide-open but with a nice effect and pretty sharp overall stopped down.
I also blacked out the type on the front of the lens.