No more occasional UI glitches requiring Alt+F2+R, so far. I'm even back on Wayland.
Memory usage seems back to normal. Now, I rarely go above 50% (8GBs installed) and don't use the swap file. It seems like memory usage had crept up under 16.1. I was usually at 70% and the swap file was in use.
I'm using Chrome, BTW. And I did a reinstall of Zorin recently.