Well, Canon may be 50 years old, but one I used to have was sharp - so I'm not sure what you base your opinion on.
Canon 50/1.2's have long had the rep of not being sharp lenses from day one. You can follow their not so great reputation wide open in the "too hot to handle" column of the old Modern Photography if you like. That is not so say some copies are sharper than others. That not so great Canon 1.2 opinion is also shared by Tom A, who has shot with most every available Leica mount lens.
I looked at your Konica 50/1.2 shots. Sorry, but they showed me nothing special. No way would I have sold your set of 28, 50/2, and 90 Konica M lenses just to get ONE fast 50/1.2 Koni lens, but that's me. Your loss in versatility trading 3 lenses for only one is HUGE. But if you are happy with it, great. To each their own.
Stephen