I'm using Wayland right now, but tentatively.
Right now there's an issue in WoW where sometimes when I move my mouse and left-click, the camera jumps to a different position, usually trying to look up.
Only happens on Wayland and it's fixed temporarily by switching between windowed and fullscreen mode. The problem comes back sometimes when alt-tabbing and refocusing the game.
There was a bug in KDE recently where some menus weren't properly appearing on Wayland, but that seems to have been fixed after my latest update.