Learning curve for Z7/Z6

Yes - Steves e-books and videos are very good. You definitely need to keep in mind that his preferences are for the kind of wildlife he photographs, and not for other genres or subjects. One of the things he does very well is thoroughly test to find out the way to use the camera to get the shot - not why it does or does not work like another camera or a Nikon from 5 years ago.

I've found the Z cameras to be very good, but you do need to embrace learning how to optimize performance. If your first choice of settings is not working, there are great alternatives by making changes in things like Focus Lock On or Focus Area mode. It's easy to think a setting does something the way it did on a D500 or D810 - and it's not that way at all.