R1_

Canon's main weakness in that department has been that when it comes to flat image profiles, your choices have basically boiled down to C-LOG or nothing - or, on any camera that wasn't a 5Div, EOS R, 1DC or 1DXiii, just nothing (out of the box, anyway).
I presume this thing's gonna come with C-LOG given the price tag, but it'd be nice if they had some Flat/Cinelike-D type profile as well, for when all you need to make are quick-and-simple grading adjustments.

4K on the A7R IV at 60MP is actually very good, it's a nice image. D850 from 46MP also very impressive. Does it pixel-peep as well as oversampled 6K? Is it as good in low light as an A7S? Not quite, but within the normal usable window where 90% of shots are it is closer than you'd think and up on the big screen it looks great.
I see the EOS R6 having better 4K than the EOS R5.
On the R5 it will probably be pixel binned 4K in full frame mode. If it is oversampled from 8K I'll be surprised, and if oversampled from 6K it'll have a crop.
Rolling shutter in 8K will be something to watch out for. It'll probably be quite bad, if you look at current fastest electronic shutter (Sony A9), that is a 24MP chip with stacked DRAM. The 'normal' 24MP chips have quite bad rolling shutter in 6K full pixel readout stills mode. So either Canon has a very fast running sensor the likes we have never seen before, or there will be a big trade off somewhere.
That's why I think its sensible to wait for the R6 specs to come out. Maybe wait until June to make a decision.
As per the R6 rumours, 1D X III specs in a mirrorless camera for $3000 would be very attractive, especially if they keep internal 5.5K RAW in there.

This is my first post here so hi to everyone.
I must say the R5 is great news for all of us that started filming dslr with Canon. And most of us do not care about 8k so much, we care for a solid 4k with more than 30fps and maybe 10bit. As a Sony current user (weddings), i would love to be able to get back to Canon asap. I must say that everytime i check in my old files some C100 footage (my favourite WDR profile), i miss it. But Sony gave us easy and inexpensive tools, HD 120 fps, 4k, and in a price that most people can buy. This is the key, the price. And there is a price point (Sony has it) that a camera can be a hit and win the market or stay in low sales. I think arround 3000-3500$ is that mark. In the wedding film industry where i am , its hard already for anyone to beat Sony. Sony managed every of its camera "issues", disadvantages, characteristics to become normal, almost a must for every wedding clip. And got many well know wedding videographers for ambassadors. So maybe Canon should make the "revolution" along with a greeat product give a better price than Sony's. And even so it will take time for other brand shooters to change all of their cameras and lenses and give back to Canon its 5d era. Maybe the R6 is coming to help there, i dont know. One thing is for sure, this year is going to be a battlefield for Canon and Sony. Who will win? The one that gives the most and cost less.
 
 

This is my first post here so hi to everyone.
I must say the R5 is great news for all of us that started filming dslr with Canon. And most of us do not care about 8k so much, we care for a solid 4k with more than 30fps and maybe 10bit. As a Sony current user (weddings), i would love to be able to get back to Canon asap. I must say that everytime i check in my old files some C100 footage (my favourite WDR profile), i miss it. But Sony gave us easy and inexpensive tools, HD 120 fps, 4k, and in a price that most people can buy. This is the key, the price. And there is a price point (Sony has it) that a camera can be a hit and win the market or stay in low sales. I think arround 3000-3500$ is that mark. In the wedding film industry where i am , its hard already for anyone to beat Sony. Sony managed every of its camera "issues", disadvantages, characteristics to become normal, almost a must for every wedding clip. And got many well know wedding videographers for ambassadors. So maybe Canon should make the "revolution" along with a greeat product give a better price than Sony's. And even so it will take time for other brand shooters to change all of their cameras and lenses and give back to Canon its 5d era. Maybe the R6 is coming to help there, i dont know. One thing is for sure, this year is going to be a battlefield for Canon and Sony. Who will win? The one that gives the most and cost less.