Love My D850!
The autofocus speed is a huge improvement over my D800e. And now I can even use Autofocus in Live View for video. In combination with my 200-500 f5.6 the autocus for birds in flight is instantaneous with Continuous mode. Also, Autofocus works much much better at low light levels. The improved ISO performance is a huge plus for this camera. In general this camera never ceases to amaze me and I am SO glad I upgraded from the D800e.
Nikon really did their homework on this one! I also LOVE my 200-500 f5.6!