Yes the R5ii is brighter but it might be the settings in the R6ii, anyhow that is not what I was looking at.
up to up to ISO 6,400 they are pretty much the same noise wise to my eye, at 6,400 the DVD with the woman on the spine seemed a bit better on the R5ii
at 12,800 and 40,000 I feel the R6ii was better than the R5ii
Of course our test is totally subjective and they are very very close.
I am happy with the R6ii and have been able to eliminate rolling shutter on both the R6ii and R7 but it is by shooting bursts when I am tracking birds with the mechanical shutter.
I set up my C1,2,3 on each to have the same Shutter speed and f stop the only difference is the shutters.
also Electronic 1st curtain seems to have very little rolling shutter
C1 Mechanical shutter
C2 Electronic 1st curtain
C3 Electronic
I really want the R5ii and will probably end up being able to justify it, like I did the RF 100-500 (still have my EF 100-400 Lii) adn the 200-800 LOL