Just to close the loop... I looked around this week and saw a lot of beat up 4th version 35 crons for what I thought was waaayyy too much money. So, since I didn't have any critically sharp current production lenses in my arsenal, and had never gotten a new Leica lens for myself, I went ahead and ordered a 35 ASPH cron from Tony Rose ("used mint!" 😉). Got it yesterday.
Now, I've shot bricks and bricks of C-41 black and white film with all my other lenses (50mm 1st version collapsable cron, 50 lux, 90 cron pre-ASPH and CV 28 1.9), so as a test I shot my normal afternoon walk with BW400CN, rated at 320 as I normally do, and the new 35 on my M6 (I figured this would be a good test as well as a worst-case scenario -- 400 speed essentially color negative film and machine processing).
My lands! This thing is SHARP. Just ungodly sharp. Reminds me of MF. Loving it so far... Precise drawing. Objective, formal description. Large and easy to control depth of field. I think I've found my 'Walker Evans' lens (just have to work on the photographer part). Zero to complain about at large apertures as well, easy to know what's in focus and the OOF areas are very pleasing to my eye (I'm no expert, but I'd say the bokeh is as creamy, undistracting and just 'right' looking as anything I've either owned or used).
Anyway, just a note to say thanks for the feedback. I always assumed any ASPH lens would be out of reach, glad I considered the (often minimal) price difference. While I probably would have been happy with the pre-ASPH version, I'm psyched to have at least one critically sharp lens in my bag to bring out when it's called for. I'm a happy camper. Environmental portraits, here I come!