So took both out to shoot the wife having her horse riding lesson today.
The D500 is very fast, the focus is very good but 10fps is maybe a bit overkill for equestrian!
The D500 is a beefy machine, side by side it’s quite chunky! That can be positive or negative depending on how you like your cameras!!
Initial impressions are that looking at unedited images the D750 retains better details even at low ISO. I was running both cameras at 1/1000-1/2000 at f2.8-f4 with the 70-200 VRII.
I didn’t realise how much more ‘reach’ you get with DX, it’s been so long! Great at the long end but sort of awkward at the short end.
I think for equestrian, as it’s not the fastest moving sport, either camera will do the job! If I wasn’t so fussy then I think I would probably choose the D500, but every bit of detail counts for me and think will end up staying with the faithful.