Joe, in 1976 I bought a 7s with the 1.2 (yeah, shoulda kept it) and I was amazed by
the quality of the central portion of the image even wide open. I used to shoot it
with K25 so I could use it wide whenever possible. The edges didn't do very well
until f/4, but that was easy to work around. I have a window light shot of a friend
taken at 1/125 @ 1.2 on K25, and with a 22x loupe you can count eyelashes--I never would have believed it.
The contrast of the 1.2 is slightly higher than the Noctilux f/1, but the 'lux had cleaner edges. Overall, I preferred the look of the Canon. Regrettably, that's the only
Canon RF lens I've ever shot with.
Fred