I think you better pump a roll of fine grain film through it. I have a 3.5 F model Xenar that's everybit as good as the 80mm Planar on my 'Blad.
Whoa, even wide open and in the corners? That's a pretty strong endorsement and not one I think I've heard before. Maybe if "good" is judged more in terms of character than technical qualities---there are some people who find Planars to look clinical, I guess.
San Diego, CA, USA
The lady of the house has to be a pretty swell sort of person to put up with the annoyance of a photographer.
-The Little Technical Library, _Developing, Printing, And Enlarging_