I agree that the RP feels (much) better when held in my hands.So would I, but my M5 now feels too small. The RP is about the same weight but larger and feels better.
However, you can't use the RP without a lens on it. And when you place RF or EF glass on it, it won't be about the same weight as the EOS M5 coupled with EF-M glass. Not even close.