That's a very glowing (no pun intended) short review of the 75 Cron. I've been shooting with the M9 and 75 Summarit lately, and the 75 Cron L looks like it's in another league.
Have you shot much with a 75 Summicron or Summarit with a digital M? I'm interested in how the older M lenses compare with the new APO Crons in terms of rendering and 'look'. The rendering of the Mandler design lenses like the 50 Cron appeals to me very much, and I'm hoping that I can get this or better if I invest in the L mount system.