Final word and my opinion on D850 today ànd in the future after more than 6 months shooting with it and approx 5500 images:• D850 is the best camera Nikon offers until today for studio photography.
• D850 is the best camera Nikon offers until today for landscape photography.
• D850 is the best camera Nikon offers until today for LV photography.
• D850 is the best camera anybody offers at this moment for macro shooters who work with non moving subjects, intentionally undercooled or etherized insects, partly because of resolution and partly because of the stacking feature.
• If you don't mind bulkyness and weight, while used WITH the battery grip and D5 battery and in good light, D850 is the best "all in one" wildlife camera anybody offers at this moment.
TMHO, there are much better options for high iso photography though:
A D750 if your budget is limited. (D750 blows away D810 ànd is significantly better than D850 at iso 6400+)
A D4s or D5 if you don't mind weight or price.
TMHO D500, -while used in good light-, is a better action camera because of the viewfinder & AF point coverage differences as mentioned in my topic here above ànd -of course-, because of native 10 fps, WITHOUT battery grip and last but not least, the 200 NEF buffer .
For people like me who prefer D810 in a combination with D500 over D850 because of the benefits it provides for my kind of photography, a very good friend of mine who is a professional photographer and teacher wrote me the following:
"The good thing about the D850? It reduced the price on the D810!
The D810 is good enough for 99.99% of the photographers out there!"

For the future though, with a Nikon FX mirrorless in my mind and if it will be as I would like it to be:
• with F mount or "in-house" Nikon F mount adaptor
• with streaming magnification possibility in your viewfinder
• with PUF and flash commander on board
• even more resolution than D850 actually provide (75MP?)
• with very wide AF point coverage in viewfinder, like Sony pro cams.
• .....
..., D500, D810 ànd D850 might become obsolete, and probably even sooner as we expect.
Just my thoughts...