I have always used my Z9 for sports and fast action but I am going to give the Zf a try and see what I think.
100% you will love the ZF, 14 fps small light, 8 stops of IBIS 10 stops of low light focus, it ticks a lot of boxes as a camera, as i said so may people who have it love it as long as you can deal with the difference in controls.
Is it a Z8 killer NO but does it need to be.
I am a DF owner with an Italian hand made leather case and i look the part LOL, i love it, only 16 mp 5.5 fps LOL just as many people hate it and say its junk, ok a D600 with a D4s sensor and a retro top bingo and a high price point, yes true, but gee i get some really awesome 8000 and 12800 ISO shots even on a 300 2.8 VR II with a 2 x TC III, but that's me.
The DF was great at the time and served me so well, Nikon dropped a new Shutter and sensor for me in it when it blew the shutter, so its got only about 5000k actuation's, not worth selling..........good travel camera on a Ziess 50mm 1.4.
The ZF is clearly highly advanced as well as different and packed with new technology, speed and features, i love it, so do many other people,you wont be disappointment.
For me i had it on my radar, other than 24 mp i would have grabbed one, but the Z8 power house at a sale price was to hard to pass up.
Also.................. sorry i just love 45 mp and once you have that you never go back LOL.
I just swapped out my Z9 for A Z 8 and its a glove that fits my hand and needs more, nothing wrong with the Z9, just big and heavy that was an issue in cases.
So far the move to the Z8 over the ZF and Z9 has proven to be correct for my needs.
My next move will be to pick up a Z7III that will have the new features of the ZF but at 45mp, Nikon knows how to milk our wallets LOL.
Only an opinion