Robin,
only a partial answer, so take this with a few grains of salt.
I used to have a pre-ASPH Summilux 35/1.4 and loved it with slide film, colour neg and B&W neg film. I sold a few big enlargements and a shot for a music CD though of course the purchasers didn't necessarily choose them on the basis of the lens's signature!
Now I have several Leica ASPH wide-angles including the current 35/1.4 ASPH version. I find that they all give a much sharper (and to me more pleasing) effect in digital use with the M8 than does the final version pre-ASPH 50/1.4 that I am using. Similarly I don't find the final version pre-ASPH 90/2 Summicron that great with the M8, though both these lenses give lovely prints at full aperture on colour film.
Not a real answer to you of course; but it looks as though the old style Summiluxes (35 and 50) are stretched to give a really good account on digital. I don't include the 75mm Summilux because that was a later (1980?) design that was always reckoned to have the edge over the earlier 35s and 50s. Hardly surprising: the 35 and 50 Summilux designs date back to the very early 1960s, and I know there are even some modern (1990s) Nikkor lenses designed just before the D2X and D200 came out that are hard pressed to do justice to these cameras' sensors. (Then again there are old designs that are better on digital than more modern ones - as you say, it depends partly on interaction with the sensor).
No experience of CV lenses at all, I'm afraid. Please be aware my comments are in part subjective; I have never done any tests.
Tom
