Thanks all. Very minor PP and noise reduction applied in Topaz Denoise, but it wasn't too bad to start with.
I'm finding that so long as I don't under expose, the D500 is very useable up to about ISO 8000 ish, ISO 12,800 requires much more selective NR, and above that it starts to break up too much. But for a DX camera, it's still pretty impressive, and not too far off my D750.