Hello,
As i see the monitor's are almost indentical, but have a difference in appearance. If i where you i would have picked the AOC monitor, its cheaper, it has 75 hz, the AMD Freesync will indeed work with the NVidia graphics card. You will lose some functionality. You can't use the active sync feature which maintains the variable refresh rate. So this actually means that gsync is not enabled and you have a freesync.
The appearance of the OAC is much smoother and the benq has a thicker bezel.
So in my opinion pick the AOC.
PS: The benq is not freesync or neither gsync, so you cant change or adapt anything so its just 60hz.