Does GSync on Nvidia work with multiple monitors yet?
Last time I tried gaming on Linux, this was the thing that made me switch. Ironically all my games worked fine, but no GSync with more than one monitor active killed me because I really like watching stuff while I game.
IIRC xorg doesn't support having different refresh rates on a multi monitor setup, where Wayland does.
Any desktop environment running Wayland should work as long as it supports gsync with the drivers you have