they offer some optimisations to the kernel and the packages that are supposed to yield a tiny bit better performance.

an incredibly small thing that rubs me the wrong way more than it probably should about their setup is that they set Plasma animation speeds to much higher values than the stock Plasma desktop uses. sure, it could be just a part of their customisation tweaks the same way using fish as the default shell is, but it feels like a cheap trick to reel in the "I installed it on my desktop and it's soooo much snappier" review kind of people. like, if your work is as good as you claim, you shouldn't need to artificially make the improvements seem bigger than they really are.