I am having really good luck with some of my older FD and EF lenses on the Canon R. I even got an adapter to let me mount a screw mount Nikkor 50mm f1.4 from the 1950's that produces some really good results. I am gradually transitioning to the RF lenses but I am sure I will continue to uses the older lenses. I have the 600mm f11 and the 85mm f2 macro and am really pleased with them. Are any of you using the older lenses and what kind of results are you getting.