In typical Canon FD built fashion, the FD 20mm f2.8 is well put together and handles smoothly, despite its age. I had the auto focus version of the 20mm f2.8, which I, and many others, do not like much, and I wonder if its design was derived from the FD version. Both have a 72mm filter thread. At least on the NEX-6, the corner sharpness seems a bit better than the EF version, but I could be mistaken, as I used it on the 1.3x sensor before, and the corners weren't very good even stopped down. Overall, I am happy with the FD version on the NEX-6, however, on my very preliminary two day use.
DVP north at night - NEX-6 & Canon FD 20mm f2.8. Click for larger.
Smart - NEX-6 & Canon FD 20mm f2.8. Click for larger.
Streetcar turning. Shot through windshell - NEX-6 & Canon FD 20mm f2.8. Click for larger.
The yellow building - NEX-6 & Canon FD 20mm f2.8.