I'm still shooting with my Opton 50 1.5. Quite nice. I think they can compare with a 1st version Summilux even if they are 10 years younger, but ymmv. I also use from time to time prewar jena sonnars. All these if they are clean are good performers, if you do not need maximum modern "performance" (sharpness is sometime overrated as a pictural quality, and if I want some a have a '53 Rolleiflex
By the way, there are also the Schneider Xenon f1.5 and f2, and the Rodenstock Heligon f2 in this time frame. I have one Heligon on a cheap retina, I have yet to try it.