Games that have problems with the previous approach might have hitches or stalls, though it could manifest in many ways.
Edit: I am running a kernel with it on, as well as Proton-CachyOS which has it opt-in. I have yet to see it make an improvement of any kind. Maybe it might help on lower-spec hardware such as the Deck.
Cyberpunk 2077 used to stall on shutdown with esync. No such problem with ntsync.
You likely won't see any improvement aside of resolving some bugs in some very specific edge cases that you may have never stumbled on personally.