HI Joe,
Have you tested the 35/2 and the 31 Limited? I'd love to see a real side-by-side comparison of these lenses. Yoshito Takinami's tests show that the FA 35/2 achieved better numbers than any other Pentax lens he's ever tested from f5.6 all the way through f11. As of last update he hadn't tested the 31 limited, but the 35/2 topped the 42 limited in corner sharpness at a broader range and surpassed the 77 limited by a wide margin. His numbers are here: http://www.bdimitrov.de/kmp/
I've had the FA 35 mm. 2.0 for more than four years. For me, it is still better than the excellent F 50 mm. 1.7 (by a narrow margin).
In fact, it is one of the best lenses I have. Flare resistance is astonishing, contrast and sharpness are excellent at all apertures, except on the corners at 2.0, but it is more than usable wide open.
Carlos
