I own the Zeiss 50 1.4 and Zeiss 135 2.8 (both C/Y mount and on an inexpensive EOS XSI). They both please and are a joy to work with. I sold a Zeiss 200 3.5 in place of an excellent Takumar SMC 200 4.0 (it appeals to me due to the price and I do not shoot with a 200 that much).
Yesterday I was at the ball park in Seattle for a rare Cubs vs Mariners ball game and this was taken with the Zeiss 135. It is a lot of fun to work with.
This is a recent example with the Zeiss 50 - this is a joy to have on my camera.