My review of the Nikon Z7 is in full swing, though I’m spending a lot more time evaluating/publishing than enjoying the gorgeous fall season and weather.
This page shows just how wildly inaccurate the placement of the zone of focus can be with the Nikon Z7 (and other systems!). Placement of the zone of focus has major implications for total sharpness and visual impact, yet autofocus can easily choose a sub-optimal choice of focus which displaces/biases the zone forward or rearward even as the chosen point is fully sharp. This has implications for total sharpness and visual impact.
Includes a discussion of how to manage the issue. In terms of reliably making more sharper images on any camera, this page alone is worth the price of admission, since these days understanding such issues is required for excellent technical execution. See also Making Sharp Images.