Obligatory reminder that this comparison is versus vanilla wine, and gamers (steam) haven’t been using vanilla wine for many years.
Versus esync or fsync, ntsync doesn’t bring any particular performance benefit. But it may bring more consistent fps, and is actually supported in the kernel and now wine.
Just don’t expect 100 more fps, or even 10.
Yes, versus vanilla wine, ntsync is a significant improvement.
Most gamers won’t see that big a difference, though. Steam has been using fsync for a long time, and vs fsync, ntsync is more correct but not necessarily any faster.