I'll answer just so I can keep quoting this post until the end of time when others talk about how it's just a Xbox sticker.
Spot any differences?
Designwise it's quite obviously more than a sticker.
But the real difference is what you see on the screens here.
The regular ROG Ally use Windows.
With this new "Xbox" Ally they unveiled this new mode, where they throw you right into the games library in a new full screen no Windows nonsense gaming mode.
And it changes everything.
It's essentially like what you have on Steam Deck but you can hold the Xbox button to swap between launchers.
We still need to see how well it hides Windows pop-ups and driver installs etc but going by the unveil it's exactly what was needed. Hopefully they spread it out so regular Windows users can use this as well. I want that experience on the living room PC.