That was a huge batch of blog posts yesterday. I thoroughly reviewed the feature set of the Nikon D850 one by one. It looks like one heck of a camera. What it will come down to is putting it through its paces and seeing just how much better it performs.
I like the fact that that it will be relatively easy to compare the D810 to the D850: same lenses, interchangeable batteries, same loupe for focusing on the back of each.
There are really only two things that keenly interest me: (1) is making the image easier and if so how, and (2) how the total image quality stacks up and whether the higher resolution is apparent. Simple questions, but #2 will take a lot of A/B to ferret out all the differences and their significance.
Still, time spent with a D850 and a few top grade lenses in the Eastern Sierra in September is a job venue that is very hard to beat, even if I am beat at the end of the day.