Hi, I have NOT used the EF 35 2.0 IS but I had the chance to get the RP WITH the RF 35 "for free" during a very good offer. I had no stabilized wide angle lens, and I have seen a need for vloggin so that offer just came in time.
I am shure both lenses perform similar which can be seen on
View the image quality delivered by the Canon EF 35mm f/2 IS USM Lens using ISO 12233 Resolution Chart lab test results. Compare the image quality of this lens with other lenses.www.the-digital-picture.com
while that comparison is a little bit tricky because both lenses are testet on different cameras. I try to "average" EF lens images between 5Ds and 1Ds mark iii for a better comparability - just looking at both sensors output.
Optically the EF version seems to be a little bit crisper in the corners and if you do not need the 1:2 macro mode and do not need minimum size it might be good to stay with the EF version which works on M cameras too. The first RF lens brings more incompatibilitys in the bag!
Thanks for your feedback.