I thought about it, but don't think I'll push the button. I have a falcon nw gaming rig in my living room right now running windows / steam big picture and an NVIDIA 3060Ti -- and it's .. fine, but long in the tooth. I wouldn't mind a more console-ish hardware experience for steam gaming, and compared to a new falcon box, this thing is cheap. I experimented with just running SteamOS on the falcon hardware a few years ago, but it was a little fussy, and I wanted to also use the system for local inference, and, and, and.
All that said, I don't think this is a good value. I'm presuming if I did a little work SteamOS 3 would be workable for me, and I have significantly more RAM, and possibly a better GPU? Not exactly sure where the GPU falls out, but I definitely believe I could buy a better GPU for less than the new box.
If it gets preferred shipment for the controller, you could buy it and sell the box and keep the controller. :) I think my controller ship date is estimated in 2027 right now.
Falcon gaming computers start at $3K, I don't think Valve is after that level of consumer with this, it's more of a "Bring the console players into Steam" move imho.