Trying Out Fedora 25 With Wayland, Early Benchmarks Included
Counter-Strike: Global Offensive was the only game acting a bit funky under GNOME on Wayland as you can see from the high variation in the results between runs. In the end the performance was close to the same as under X.Org, but when launching the game on Wayland there was a GNOME pop-up thinking the game was hung (it was not) and other disturbances.
With Dota 2 the performance came out to basically the same.
For the old OpenArena game, the performance of GNOME on Wayland was close to the X.Org default performance level. OpenArena is still using SDL 1.2 and thus clearly still going through XWayland.