I'm having a hard time deciding whether to use X11 or Wayland for my KDE / Plasma session as I seek the best from both worlds. Wayland has the advantage of being visibly faster, to the point where you can see the mouse cursor and desktop effects working more smoothly. However it has the disadvantage of being a lot more buggy and requiring several tweaks to prevent session crashes, as well as missing features such as no proper clipboard functionality. While I managed to tweak my desktop settings to prevent the base crashes, I'm now facing other major issues that make me ponder trying X11 again... yet I don't want to go back to the ugly slow renderer, particularly now that I have an 144 Hz monitor and the eye painfully picks up on how much slower it was!

I figured I'd hope for the unlikely and ask: Is there a way to tweak X11 so that it can look and work as fast as Wayland on an 1080p / 144 Hz monitor? I remember KDE / KWin once had a setting called EGL which did in fact make it go as fast, however it was removed years ago and implemented exclusively for Wayland. Is there no other way to get the same smooth rendering to work?

I have had much the same question: is Wayland, which is more elegantly programmed and, when it works, faster, given that it has so many issues?

What I find is this: each half-year of update of Ubuntu, Wayland, Gimp--and all this in Neon KDE Linux, my preferred Linux--Wayland tends to work a little better, with a little fewer issues. A forum like this can help those who are rooting out the last Wayland issues.

In short, I have decided to use Wayland whenever I can, because it is an elegant approach that little by little seems to be more in the future than X Windows is. But something simply doesn't work under Wayland, like Kazam video recorder and a number of smaller programs.

Even Gimp, which is a giant program maintained by many, has sudden pauses under Wayland, or elementary Window operations suddenly doesn't work at all. In FileZilla, the right-click may not work. And so on.

The KDE Neon developers should note that even the taskbar, at least when set to autohide and given many tasks like starting multiple instances of VLC, Firefox and other such things, tend to stop working under Wayland. Even when it does work, it is obvious--eg when opening a second instance of VLC via right-click menu--that the graphics hasn't been worked through.

By and large though, given that one learns workarounds and sometimes logs in to an X session, KDE Neon works superbly well with Wayland, and for sure better and better in upcoming seasons.

A little update on this: I found part of the reason why X11 wasn't as fast as Wayland for me. It's better now though a small difference is still perceptible between the two.

https://bugs.kde.org/show_bug.cgi?id=423230

Since switching to a 144 Hz monitor, I visually noticed that desktop compositing still runs at 60 FPS in the X11 Plasma session (doesn't affect Wayland). Normally it should run at the monitor's active refresh rate.

After some digging on the issue, I found a workaround that fixes this problem for the time being: You need to edit ~/.config/kwinrc and manually add MaxFPS=144 under the [Compositing] section. I can confirm this gets the compositor working at the proper refresh rate and visibly appearing smoother, however that should be detected and happening automatically.