I've run ChimeraOS for a while now. It's such an impressive experience. You really just install it and it works.
I'm using a NUC8 and PS4 controller. The amount of effort Valve have put into the Steam Deck really shows, I guess game developers are encouraged to make the Deck compatibility good, and ChimeraOS takes advantage of that.
ChimeraOS has an immutable root filesystem which does A/B updates, so it's much closer to having the Steam Deck OS on a PC than a regular distro running Steam with Big Picture.
It's also got a web interface (called just Chimera) which lets you install stuff from Flatpak, or add ROMs which it integrates with RetroArch and nice pictures so they appear in the Steam interface as a regular game.
I'm using a NUC8 and PS4 controller. The amount of effort Valve have put into the Steam Deck really shows, I guess game developers are encouraged to make the Deck compatibility good, and ChimeraOS takes advantage of that.