Always wanted one of these lenses, I finally took the leap and bought one second hand from here. It works ok at wide open F2 but there is noticeable coma at the edges so I stopped it down to F3. Paird with the Astromechanic EOS adapter (VERY pricey but VERY sturdy), there is no noticeable tilt with very flat field. I am going to have some great fun with this little lens. It also SOAKS light like nothing else at such a fast F ratio.
Taken with the 1600MC-Pro camera since I couldn't be bothered with filter imaging that night. I'm waiting for a clear night to try it out with narrowband filters.
60x120sec
Astrobin link here
Thanks!