So the Z8's out, and assuming the new features of the Z8 make it to the Z9 in a FW update, what's the $1500 get you? As a Z9 owner for the last year I'm wondering for new buyers, or even for my own satisfaction, what benefits does the Z9 have that could make up for the additional $1500 cost - I saw Thom's list, but he's missing some differences that matter more to me than the ones he has listed.
If I was to buy a Z8 I'm not sure I'd bother with the MB-N12 as it's not clear that it provides any additional features other than battery life and a vertical trigger, on the D800E it increased shutter speed which was a key reason I bought the battery grip, but this just looks like a massive, and ugly, battery extension. Based on the pictures it seems that he Z8+MB-N12 is huge compared to the Z9. However, for 8K shooting perhaps the extra power is needed, I think that'd be the only reason I would consider such a big ugly grip compared to the elegance of the Z9 design and amazing battery life. I suspect the Z9 is also much lighter than the 8+Grip.
The question of 8K/60 thermals, and the time you can really record before it shuts down is a big open question, they claim 90 minutes for 8K/30, I haven't seen any claims on actual 8K/60/RAW recording.
The GPS is nice, although I haven't used it much and wouldn't associate much value to it.
However the real cost neutralizer as I see it between the Z8 and Z9 - for my usage is the second CFExpress slot. I need 6TB of storage for 4hours of 8K/60 content, needs to be portable, and I won't have a laptop on a long trip. The best solution I've found for the Z9 a single $900 fast 2TB card, and some cheap $170 2TB M.2's and M.2 to CFExpress adapters that I can copy files at 400MB/s between the slots. So back at my hotel I can copy from my main slot to the second slot onto these much cheaper SSD adapter cards. With the Z8 there is no second CFExpress slot, so the copy action will only work at ~130MBs at best, taking 3x longer, and the cards are vastly higher in cost too, meaning in all reality I'd need to be buying 3x 2TB CFExpress cards, the extra two cards would cost $1500 and match the cost difference between the Z8 and Z9. More sensibly Nikon could perhaps enable USB-C drive attach in firmware and completely eliminated this issue altogether, in fact, perhaps the Z8 does this anyway, which would be a huge improvement over this silly set of hoops I'm using.
Unless there's any AF performance difference I suspect they are going to greatly reduce their Z9 sales, and perhaps their volumes had dropped anyway so they needed this to keep driving unit sales.
Roland.