I run an R3 and and R6, each with a control ring adapter. Check my sig for the EF lenses and accessories. I can state that I enjoy remarkable success with all of them. RF has an advantage in terms of AF speed for USM -variety and VCM lenses, from my limited testing, and in some cases there's a sharpness edge, but nothing I'd pay $1000+ extra for unless my mortgage depended on the outcome. Turn on DLO for sooc improvements (I use max DLO, but the fastest things I shoot are sprinting deer and galloping horses). Especially for Macro I really appreciate the manual focus with the EF lenses as it stays put and can't be damaged when the camera sleeps, gets turned off, undergoes a battery swap, etc. If you're on the fence it's worth hauling your camera to the local store and testing both EF and RF equivalents. Stuff like the 100mm macro should still be in good supply around the place, and right now Canon / vendors tend to run early summer specials.