To me, this isn't an "upgrade" from the D500. It's a small step forward here or there, and more steps backward.
Concerns and observtions vs the trusty old D500:
Old 20.9 mp sensor, it is probably time for an increase in MP.
11 vs 10 FPS with mechanical shutter = basically the same. Electronic shutter15-30 but will there be rolling shutter problems? Also, if I am reading correctly, top resolution files can only come from 11fps or slower.
No XQD or CFExpress card slot, only one SD slot.
Tiny battery instead of the EN EN15 format
Doesn't look like it's built very robustly, but obviously I haven't held it in my hands.
Real world focusing feedback will be interesting. Can those of us who shoot fast action get the performance we need? It certainly looks promising.
No IBIS is disappointing, that would have been an important upgrade.
Looks like the control buttons are very customizable, which is great.
No top LCD, I know they aren't "necessary" but I like them
Controls can't light up in dark as on the D500.
SO while this looks like a great camera for the price, it sure isn't a replacement for the venerable D500. The again, how could we expect that at this price point?
Just some rambling opinions.