Frank:
The picture could have been taken by my D810 or other bodies that I own. The lighter weight package of the Z6/24-70 S encourages me to take it along on my walks. The live histogram allows me to tweak the exposure on the fly without having to chimp, as does the EVF. I have really enjoyed trying out some of my older glass, which now has image stabilization, and really good tools to aid manual focusing. It has been stimulating learning how to work with the different strengths of the Z.
It won't replace my D4 and D500 for birds in flight, just not there yet. But I am looking forward to some use for my loon photography, where it is a constant battle to control the exposure because of the high dynamic range of the bird. Loons don't fly much, so the top notch tracking isn't as important of a skill.
Randy