One of these bad boys. Obviously the first thing I played was the near 30 year old PS1 game Final Fantasy IX (though with Moguri Mod so it looked fab)
Feels amazing, just a right amount of heft (though I wonder if it had more battery in that would have been an okay compromise). Only issue is a couple of the software side of things but can be easily tweaked - mainly in that the library has no filters on it except an overall "Great on Steam Deck" and your pre-made collections, so I'm having to make up some collections on the PC to filter a bit more finely. Also means you have to click through to find what the install size will be - which for a few games can mean that while they'll play great I ain't installing them due to being half the size of my storage. Which at the moment there's also no background/standby download and install so you need to set it away and leave the deck chugging along.
But otherwise enjoying - great for the little games. Also plentyu of 3D printer support too so docks a plenty for major brand of USBC hubs (shame that british plug is a bit too thicc to fit in the back strap - there's US n EU plug cable tidies that fit right in the snug of the case). And support for PS Remote Play, GOG, Epic etc with quite a simple bit of work (at most some copy pasting to the Terminal).