The (Contaflex) lens is sharp and with Kodachrome you can see the difference with pictures taken with this lens and the Canon 50mm f1.8 lens SLR lens.
Sooo...do you mean the Contaflex beats the Canon SLR? There was an article in one of the mags (US Camera?) in the late '50s-early '60s comparing SLR photos to Leica or Nikon or Canon interchangeable lens RFs. The conclusion was that locking the mirror up made the differences in sharpness disappear. I think they enlarged prints to 16X20. OTOH, if you think the Canon SLR photos are better.... I used a non-quick-release SLR for years, and I never missed the QR, though I didn't do sports. I could do kids and college parties, though.
Idiot that I am, at 14 or 15 I bought an Exakta V w/F2 Biotar (non-auto, non preset) instead of a 1940 Leica F (also known as III - NOT IIIF) with an F2 Summitar. My dad was horrified that I was contemplating buying an almost 20 year old camera instead of the 4-5 year old one. I updated to an auto F2 Biotar in 1962 when I was making 150% of minimum wage in the 6 months between HS graduation and college. I traded the Exakta for a new Minolta Autocord 7 years later, the 1st day of our brief 'honeymoon', then sold the Autocord to the camera dealer I was working for when I realized my infant son was going to cut deeply into any darkroom time. Snapshots only since 1972.
I went through several 100' rolls of 35 mm film during high school. I never liked 35 mm photography - I much preferred the thought required when dealing with 12 shots on a 120 roll.