Don't expect reliable and fast AF from Canon lenses on S*ny bodies. I have Metastones and Sigma adapters and dozens of FW updates.
Canon EF lenses work very well with the Canon EF-RF adapter, in some cases better than they did on EF. Don't buy weird brand EF-RF adapters.
Some of the new RF lenses are optically worse than the EF lenses that they replaced. It's rather sickening, but weight is more of a priority than image quality according to Canon. Other lenses (180/3.5 macro, 500/4s, TS-Es, etc.) have not yet been produced in RF, so I'm using about 50% EF vs. RF. Of course there are some really nice new lenses like the RF 28-70/2, 100-500, and 70-200/4.
I only use S*ny lenses on S*ny, but that is mainly the specific combination of the 200-600 on the a7RV.
Canon EF lenses work very well with the Canon EF-RF adapter, in some cases better than they did on EF. Don't buy weird brand EF-RF adapters.
Some of the new RF lenses are optically worse than the EF lenses that they replaced. It's rather sickening, but weight is more of a priority than image quality according to Canon. Other lenses (180/3.5 macro, 500/4s, TS-Es, etc.) have not yet been produced in RF, so I'm using about 50% EF vs. RF. Of course there are some really nice new lenses like the RF 28-70/2, 100-500, and 70-200/4.
I only use S*ny lenses on S*ny, but that is mainly the specific combination of the 200-600 on the a7RV.