If the R5 and R6II cost the same...

...and you didn't care about video, which would you choose and why?

Depends on use, Might go for the R5 if I only would be shooting landscape.
The R6II might be the better allround camera (has also higher fps 40 FPS with electronic shutter) the R6II also has a better buffer for that high FPS

Not only shooting landscape, but "ultra high" fps aren't needed -- 10 fps is more than fine. Seems like the R5 is the way to go -- thanks! However, what I really want is an A7R5 + Tamron 35-150 / 2-2.8. However, that's a bit much, and I was thinking of maybe getting an R5 to use with my Tamron 35-150 / 2.8-4 VC (which I use with a 6D2, now) and then upgrading the lens when Tamron makes the new version for RF mount in the future (unless Canon goes full Apple).

R5 - I don’t need 45 MP - but ability to crop out and give the same resolution as a 20MP apsc with also all the FF advantages when can fill the frame is key to me in wildlife. At equalised resolution(downsize R5 to 24MP FF) there really is no R6II high iso advantage of any significance

As with everything, so much depends on what you’re shooting. For my birding/wildlife, the R5 has obvious benefits. I’m happy with the body and will be using it until the R5ii makes its appearance. Unless the R1 bowls me over that is. We’ll see!

The R6ii is my event/sports shooter (replacing the R6). The main reason for the trade-up was for the improved AF selectivity. It’s much easier to choose which subject to lock onto. As far as actual AF keeper rates, I’d say that all threee bodies are very close. The difference is more in the features rather than capabilities. (BTW I’d place the R7’s AF right up there too).

IME the IQ difference between the R5 and R6ii is pretty much a wash. They both kick butt. A little more detail in the R5 images (when you do everything right), but it really depends on one’s output requirements (and cropping needs). I do highly recommend DxO’s PL6 no matter what body you choose.

Bottom line, IME any of these 4 bodies will be fully capable. I’ve put them all through (action-shooting) torture tests. It’s really DIGIC-X that’s the enabling common denominator. You just have to decide based on specific feature sets! And price.

Best of luck!
J&H

R5. Whether or not you need the extra resolution it's an advantage. Cropping is underrated.

This would be a tricky one for me, now that I own the R6II and have experienced the truly amazing performance. If I were offered a brand new R5 in exchange for it, I'm not sure whether I'd take it. Other things being equal, I think more resolution is at least a slight advantage, but other things are rarely equal. The R6II doesn't just have (even) better AF performance (and implementation), though. A pretty important feature, that R5 users have been vainly asking for since it came out, is the ability to shoot e-shutter at different rates. E-shutter is very useful for all kinds of shooting, and the ability to use 5fps, instead of the ridiculously high rates (20 or 40) or single shot is a pretty important feature to me. There are also cool features like RAW burst with pre-buffer, and in-camera focus stacking (which I also have on my R7). Maybe the rumoured further firmware updates will bring some of these features. If they did (intermediate e-shutter burst rates, focus stacking in-camera, ability to initiate tracking from any focus mode), that would probably tip me towards taking the R5, in this purely hypothetical scenario. Basically, if the R5 had pretty much everything the R6II has, plus the 45MP sensor, the choice would be easy. As it is, I'd probably stick with my R6II.

Depends on which one has a viewfinder I can tolerate.

I've never been able to find an R5 or R6II locally. I tried the R6 (not II) and found the viewfinder largely unusable.

I'd be interested in an EVF camera if it could produce 30MP files from an APS-c-sided frame, if it had a viewfinder that I found usable and if it was compatible with my EF and EF-s lenses. I guess by specs, the R5 is the closest to that but since I'm so sensitive to viewfinder performance, I'd never buy one sight unseen.

When talking “needed”, none of this is really needed. It’s all wants.

I went to the zoo with my kids where they had a Cheetah running demonstration. I had exactly two passes of the Cheetah to get the shots I wanted. I didn’t need the shot. But I wanted it and 10 fps would have made it a lot easier to miss than 40.

So I have three shots all within a fraction of a second where the Cheetah is near full stretch and totally off the ground. I also have three shots when the Cheetah is fully closed up and all four legs off the ground. One of each of those is the exact moment. The others are just slightly less than perfect. Probably would have been good enough in the past.

I know they aren’t the first successful shots ever of a Cheetah running. I know I could have got lucky with a single snap. But 40 fps sure made it easier. Think of your child pitching a baseball. Or kicking a soccer ball.

Now I didn’t opt for the R6II because of that. But it’s still pretty cool. My “not needed” for the R5 was anything 8k and the larger file sizes of the 45 megapixel sensor. And the more expensive memory cards. I don’t heavily crop or print any bigger than A3+.