If only Canon asked!!!
1) The hot shoe is fragile. Hasn’t been a problem for me, but it worries me a lot every time I use flash.
2) No zebras in Stills mode.
3) When the meter times out (mine is 4 seconds) the controls do not time out. So as I carry the camera, the exposure comp or focus point gets set way out of range. This happens to me a lot. The controls eventually do time out, after perhaps 30 seconds, but by now my exposure comp has been knocked +3 or so.
4) (sorry). Some of the menu options need to be better organized and more clear. In particular, the process of configuring the camera to save to two memory cards is very confusing. The process of enabling the AF joystick requires 3 or 4 setting changes. Using HDR or PQ requires several setting changes across several different menus, and it’s not clear what happens.
5) (very sorry). If I’m using AutoISO and I dial in a Manual ISO value, I cannot dial the camera back to AutoISO. On the 5D Mark IV, I just dialed a notch below ISO 100 to get AutoISO, but on the R5, I need to use a Menu item to set it back.
6) Ok, this is getting ridiculously longer than 3 items and I’m truly sorry, but Canon needs to recompile DPPro for Mac so that it takes advantage of the multithreaded, multi-core RISC processor instead of running in single-threaded Intel emulation mode. I’m not saying this because I’m a nerd, but because it’s so slow that I can’t use it.