The time gap between the 5D Mark III and Mark IV was about two years, same as the time between the EOS R and the R5. More so than previous releases, I am starting to feel that I may really want to upgrade to the Mark II of the R5 line, and given that I appear to have plenty of time to reconsider my preorder (it's looking like 1 month on the low end, and 3 months on the high end), I've been considering whether the right move is to just wait out this first revision, with the hope of seeing an R5 Mark II come 2022. The most unfortunate part about all this is the lens mount transition lining up with the switch to mirrorless. I was hoping to start transitioning to RF now, but under my new thinking that would mean getting EOS R to hold me over as there's probably not going to be an RF-to-EF adapter to use RF lenses on an EF body. I'm curious if anyone else is having similar thoughts along these lines.