I think Nikon hit one out of the park with the Z7. I can almost feel the Canon exec's sweating bullets, as Canon is supposed to unveil their own mirrorless full frame camera soon, which I doubt is going to be as capable as Nikon's version.
As for me, I am going to use my original Sony A7R into the ground as its svelt size and portability is unbeatable, as newer mirrorless full-frame cameras continue to get larger.
Sony A7R vs. A7R III size
Sony A7R III vs. Nikon Z7 size