For my gaming rig I use Mint Cinnamon with the Xanmod kernel and kisak-mesa PPA for bleeding edge performance but otherwise a very low-maintenance, convenient system.
For my personal laptop (ThinkPad T480s) I use Arch with KDE. For my various mini PCs used as servers, I use primarily Debian derivatives, except for my Mac Mini which runs Asahi Arch so I could optimize the use of its 8G of RAM.
Xanmod has a bunch of little tweaks, mostly I’d say it helps with frame pacing more than anything else. It’s only maybe 1-2fps difference most of the time, but it’s very close to the upstream mainline kernel in terms of release timing, whereas Mint keeps to LTS kernels.
Likewise, the kisak-mesa PPA just keeps you more up to date with the upstream package version.
IMO the biggest differences are responsiveness, frame pacing, and getting to have access to the latest fixes/features ASAP while still getting to use the very stable package versions for the rest of the system.