For many months I have agonized over the R5 versus my 90d as well as the 5D Mark IV and the 7D Mark II both of which I picked up used through POTN. I am still learning all the ins and out of the 5D4 and 7D2. The thing that interested me on the R5 was the animal eye AF and it's ability to track birds extremely well, those two things were the main reason I was thinking of switching, as well as the ability to shotgun more because of a bigger buffer. Then I started hearing that it still could get confused with a small bird on a confused or foliage background so would it really be that much better than what I already had. Also the fact that I love the controls on the cameras that I have
It might be teaching an old dog new tricks but the 5D4 The 7D2 and the 90d controls are close enough and when I need a flippy screen I have the 90 when I'm looking at shooting in lousy weather I use the 7D2.
I also like the crop sensor of the 7D and the 90d that is why I'm waiting to see what the R7 turns out to be the rumors I've heard really interest me because I like the extra reach of the APS-C sensors because at times I tend to be the king of cropping
With my feeling eye sight, I depend on auto focus to try to get sharp pictures, my left eye is really bad the right eye is going there it's getting harder to read and harder to work on the computer to process what I shoot.
So far I have about 50k clicks on each camera so they should last a while yet.