I don’t think you will find R5 owners who don’t like their purchase. I seriously love this camera.And here's dumb old me sitting here really happy with my camera.
I had kind of a weird auto focus thing going on but a camera reset seems to have fixed it.
I use my 7D2/5D4/EOS-R/R5 interchangeably and haven't done a whole lot of custom mapping/whatnot - I learned what did what and matched up what I could between them and off to the races. If I let a camera sit for a while (like my 40D or Rebel) it takes a couple of minutes to remember all the ins and outs of how it works but nothing major.
I guess I'm not advanced enough to know any better.
What most won’t love are the limitations and what it takes in buying or carrying additional gear or process changes to make up for the limitations when other like products in class and price don’t have them. There’s also little bugs here and there that feel easy to fix, but again it’s more to do with the $4K price that would suggest the little things be ironed out(mentioning random shutdowns would be beating a dead horse).