Hi
I have brought the Tamron G2 as my go to zoom on my D850 and once I had fine tuned it with 70mm being 0 plus 200mm +8 i settle for a +5 it made it bit sharper then the factory settings.
Seems to work fine on my D7500 as well, sharp from corner to corner quick to focus with best image quality when stopped down to f4 build solid and being in the outback where their is red bull dust everywhere its still dust free.
I had the Nikon 70-200 f2.8 V2 for around 4 years with my D810 and the Tamron image quality is shaper but possibly a little slower to focus on infinity but it close.
The image between my Crop and FF is down to the sensors as this lens is very sharp on both of my camera bodies and if I run my D850 in dx mode I can’t tell the imagers apart.
Cheers
Davoxt