I had the chance to play with EOS R a bit. My intention was to go through the typical usage/workflow to see how well it coincides my current style. I currently use 5D3 and used 60D to 5D4 to D7000 to D810. I love many features about the R, but some of the points the person in the video as well as others mentioned here is correct in their assertion. Can we get used to the new layout? Sure. But I felt Canon nailed their layout with their FF over the years and is the sole reason I chose to use Canon bodies over Nikon. It just works. So some of the choices for button placement and removal seemed a little strange. Why break something that already works.
I have a medium sized hands, the grip on EOS R is fantastic, I compared it side by side with Nikon Z (okay, grip wise), and A7III (sucks grip wisel). That being said, I felt a lot of placements could be tweaked for better usability. I mentioned in another thread, the mode dial on top is ok, but I felt I had to loosen the grip a tad in order for my thumb to reach it when I am previewing images on the back of the screen looking down. If you used their DSLRs there wheels on back and top work so well without even compromising the grip, I cannot understand why not use what already works.
The AF ON felt squeezed so much into the corner that you have to move your thumb closer to the edge instead of having your thumb at natural position which would rest closer to where the M-Fn bar is. I tried assingning the touch screen AF on the top right corner so I can use my thumb to select points. There is no way you can reach the left corner of the AF area with your thumb while you are looking through the EVF without letting go of the grip. Also the nose gets in the way a bit. Now I shoot in extreme temperatures from time to time, I cannot see its usability if I have my gloves on. The joystick is a MUST! I dunno, I will probably buy R or the next one as it has more pluses than minuses. I feel it will take a generation or two before Canon nails down the UX for their mirrorless. But it is a good first attempt.