I got an AOC 2K 27" curved that is G Sync compatible and it's been wonderful. There is an official support list for them (somewhere) and I highly suggest you shop while referencing it.
I have another 24" 1080P Acer model that isn't on the list, is officially FreeSync, but I can force G Sync through the Nvidia CP. It works "mostly" well and would suspect the bad feedback being seen is related to that aspect.