Well, I do not have direct experience with the Canon 85/1.2 L lens. I have seen many prints from this lens in a Canon 1Ds1 but I have never seen it with colour film. It is certainly a lens I am eager to try.
C Sonnar 50 1.4 is the lens of choice if you use a lot of 1.4, otherwise go for the ZM Planar 50 f2. The f2 of ZM 50 f2 is better than the f2 of C Sonnar, so are the other f. nos.
ZM 35 f2 is a bit embarrassing at f2, but from f2.4 onwards, it has a breathtaking performance. I really like this lens. This lens performs really well at small apertures. On the other hand, ZF 35 f2 has a good f2, but do less well in small apertures.
I should believe C21 and 18 will be good. In fact, the lens ZM 21 f4 will be better than ZM 21 f2.8. Zeiss knew she could compete with Leica at the wide angles, this is why she is making so many of them at the moment. I am really surprised at Leica when she announced the Tri-elmar 16-18-21. She should have made some primes instead. It is over for Leica as far as wide angles is concerned.