Yes i feel different is a good way to describe it with the D6 Z9, i mean both are awesome.
I use a D6 rental exclusively for low light high iso critical fast action shoots where i cant afford to stuff up or fail on.
More likely i am the only one feeling like this but i actually prefer using the D6 over the Z9 i have, i don't have to concentrate so much on what i am doing, that's just me of course.
I do love my D850 and previously D6 D5 D4s...yes the Z9 is awesome but very different for me, i just need to concentrate all the time to get the best out of it. Again that's me.
Lovely record shots by the way
Only an opinion