There are only two use case scenarios I could only imagine for this thing, first to use it as a very compact desktop replacement, it has all of the bells and whistles to be used as a desktop PC in a very small form factor. And second would be as a small compact desktop replacement that could be packed away into a backpack and taken while traveling.
But it looks simply Way too big to be used comfortably as a handheld! I doubt it would be very comfortable taken out on a airplane or on a bus or on a train...
Plus with that cpu and gpu power the heatsink must be pretty heavy...
I have a Win600 that's slightly smaller than a Steam Deck and I still feel that it's pretty big!
Still, given that this was a DIY project I gotta hand it to them for building this!