Handheld PCs come in two camps: SteamOS (the Steam Deck) and Windows (the ROG Xbox Ally and similar).
Game stores
Windows handhelds run every PC store: Steam, Xbox app and PC Game Pass, Epic, Battle.net and EA. The Steam Deck is built around Steam, and other stores need workarounds.
Software
SteamOS is simple and consistent. Windows offers more freedom but more fiddling. The ROG Xbox Ally’s Xbox full screen experience makes Windows feel much more like a console.
Performance and price
The ROG Xbox Ally X is faster than a Steam Deck but costs much more. The Steam Deck OLED is the better value if your games are on Steam.
Our take
If you live in Steam, choose the Steam Deck OLED. If you rely on Game Pass or use several PC stores, a Windows handheld like the ROG Xbox Ally fits better.