While not available in stores here until the end of September, the local had one on display and I spent a few minutes working with the new mirror-less full frame kit. Then for fun I tested it with a non-cpu manual focus 28mm Ai S in aperture mode.

You can read all the specs online if interested... but my first tactual impression is as of a small dSLR with lots of buttons... lots of buttons.
I tested the kit with the 24-70 Z mount lens (and the aforementioned 28mm Ai S using the adapter). The Z7 kit with body, lens, and adapter lists for Yen 534,600 (just under USD 5,000) so it's not inexpensive.
The Nikon Z6 will be released later at a lower price point & "less features"...
If you have any interest my suggestion (as always) is to take all comments with a grain of salt and try to get hands on...
Casey