In terms of Noise and DR, Bryan has posted his results, as has Photons to photos.

Big picture statement, no real change. Very similar to each other. The R5 break between ADC is at ISO 400 and it is at ISO 800 for the R5 II. I prefer the ISO 400 change, I find having ISO 400 being similar to ISO 100 on the R5 very useful.

There isa slight hit to DR for ES. Given the claims that ES is 14 bit, that was a unexpected.