timballic wrote:
....but what about Leica? There seem to be a plethora of their 90mms about?? (The Leica APO Macro-Elmarit-R 100mm f/2.8 (E60) is 100g more than the Zeiss, so I've dismissed it). I want close focus but don't need macro. How would they compare with the above? Please be specific with version, as there seem to be so many. Also I'm not made of money, Leica usually being out of my range.
Sorry not being able to actually help with your Leica question, but I can tell that for what you are looking you will waste your money on Leica Elmarit-R or Elmarit-M 90mm f/2.8. I have both, have had 90mm +10 years and 2015 got M-version as well. Great lenses, but they start to "sing" f/4 or f/5.6 and excel on other stuff what you are looking for.
I haven't yet tried Summicrons (=f/2 lenses), but based on photos I have seen on Leica threads in past 10 years the Summicron (=f/2) model without APO is not for me and I doubt it's what you are looking for either based on your requirements. I would like to experience 90mm APO, but they are damn expensive.
Contax G90 is pretty good wide open on qualities you are looking for, but ergonomics are awful and for top performance you need to work with adapter to avoid sensor chamber reflections.
Contax C/Ys 2.8/85 and 3.5/100 are both pretty good wide open. I have had both and I strongly prefer the 100mm, but 85mm is smaller size and pretty good as well. Naturally any of the f/2.8 (or 3.5) lenses can't have same subject and back-/foreground separation, what your Z-series MP 100 had.
Samuli