I have some window resizing/tiling/moving lag spikes with KDE and notifications lag the whole system with kde/gnome. This sis apparently a bug in the nvidia driver. Besides that games run pretty much perfectly. The card gets hotter than on Windows with PoE but that's basically it. For reference, I play PoE, league (for now), ffxiv, D2 mods, last epoch, some indie games, bg3,... I have a 3080 card and a ryzen 5800x processor.
Always using the newest proprietary driver of course.