I got hands on with the Lenovo Legion Go S handheld PC with Valve's SteamOS—and it seems like a bit of a winner to me
SteamOS is Valve's own Linux-based operating system for handheld gaming PCs, which has so far only officially resided on the Steam Deck. It has been port-able to other devices, but no one has officially taken on the OS for their own device. Until now, anyways.