In general, I think the 20” dark looks best on the R1T and the 22” looks best on the R1S. However, how you plan to use the vehicle should also weigh heavily on the decision. If you plan to be offroad much or tow a heavier trailer, then the 20” are almost a necessity. If it’s a mall queen or you want the best on-road performance, then 22” will fit the need. Personally, I’d shy away from the 21” just because it’s currently a size exclusive to Rivian which will mean more cost and less options when you go to replace them. I doubt the energy efficiency difference between the 21” and 22” will be more than 5%.