I've had trouble with my Gsync monitor in the sense of it ruining some games that don't properly react to it maybe (7 days to die alpha indie game) and realize Vsync is better in some cases where my fps are above the monitor refresh rate. But I run at 4K so it's not the same.
In my opinion, since you can disable gsync easily even during a game, and the extra cost isn't as much anymore nowadays, if you buy a monitor on sale, yes, get a Gsync monitor it helps for games like Witcher 3 which you can't run at over 144 fps, unless you lower details on the game.