GPS - Smartphone apps and pp synchronisation work so well that the absence of GPS on the Z8 is irrelevant.
I have a Z9 and two Z7II bodies.
I have pre-ordered the Z8, but I am having second thoughts.
If the Z9 and Z8 had been released at the same time, I would have gone for the Z8.
But they weren't.
Mrs A, an artist, sometimes uses the Z7II, but tends to find it rather heavy.
The Z8 is even heavier.
The Z7II image quality is stunning, and, as I have shown in the Thomas Heaton Iceland thread, can take excellent action photos. As it is quite light, it is more useful to me whenever I do not need the superb Z9 AF.
If I sell the Z9 I will raise enough cash to pay for a Z8. But lose the advantages of the pro body.
My current thinking is that I should have a superb action and wildlife camera (Z9) and a lighter body for general use. The weight advantage is not enough to make me swap a Z9 for Z8 at roughly no cost or financial benefit.
So I think I will stick with what I have and cancel my preorder.
I reserve the right to change my mind.
YMMV.