Unrelated specifically to emulation but I also recently got a GSYNC-compatible monitor and it does work. It has a feature called Low-Framerate Compensation where, when gsync is activated, if a game's FPS falls to below 40fps or so then it will double the gsync'ed refresh rate, so that for example Mario Odyssey running at 30fps on Yuzu, gsynced, will use 60Hz signal. This is actually really fucking nice because you play the game at the gsynced framerate but without the latency of the lower refresh rate. At around 50fps or so it reverts to normal behavior and syncs 1:1 the fps with the refresh rate, so 60fps = gsynced 60hz; however this LFC feature ended up being REALLY good for Emulated games that run at 30fps.
the way gsync works, basically, is simple: it matches the refresh rate to whatever the frame rate is, down to the decimal, every single milisecond, so this means the game is always "synced" regardless of the framerate fluctuation and this means it's smooth and doesn't camera-stutter or hiccup like games do when they're not 'synced' to the refresh rate, and additionally there is no sudden big STUTTER that happens when normal v-sync is being used and the framerate falls below the refresh rate... HOWEVER (and I want to stress this) it isn't magic. 30fps still feels exactly the same as 30fps does on a normal system. It does not magically make lower framerates play or feel better. What it does do, however, is really really really fucking nice. Not having to worry about your frame rate fluctuating or suffering a sudden drop is pretty damn magical, plus you never again have to give another thought to vsync usage, which that alone can be a huge worry off the mind. Just turn on gsync and play.
Can't really say right now if it's worth the extra money you'll pay for the monitor to have the feature... it's tough to judge. For me it was worth it. It gives me both very smooth gaming, always synced, no worry about fps fluctuation, but it doesn't make your games run better, it doesn't eliminate game-related stutters, it's very much a "bonus" feature. A very, very good one, a REALLY good one that can improve your quality of life during a gaming session, but it's not like upgrading your GPU or CPU, it's not THAT kind of upgrade.
EDIT: Oh forgot to mention that when gsync is on you don't have the latency you'd get from using v-sync, so for people like Great Deceiver it's also a nice thing to have. I can tell you right now, as someone who normally used v-sync enabled on every game for years and years (I hate camera stutter) when I loaded up a game with only Gsync on and no vsync bruh... it felt like I was fucking flying through the game. It was quite dramatic. The lag added by normal vsync is no joke!
So for people who find the added lag of vsync uncomfortable but also want the smoothness of vsync then yes, Gsync is exactly what you want. That alone might be enough for you if you want as least latency as possible while also having zero camera stutter.
The monitor I got is the Nixeus EDG 27, snagged it for $335 on Amazon.
