Is it worth it? Yes!
Long answer: YYYYEEEEEEESSSSS!!!
More serious: you're saying it... If you already have a library of games to try, it's a great product. Compatibility is generally better than valve's own findings, though it might be a bit finicky to get it to work. But even then we're talking of at most 40% of their library (check steam or protondb for compatibility).
The interesting part is that I don't use it so much for on the go (though i did play dead cells on the train yesterday) but for constant on/off switching. Joys of being a parent, i guess. But really: it's like a smartphone or tablet in that you just pause and resume whenever.
It's also worth noting that it's already competing with just about any pre-hacked console in ease of use. Emulation up to wiiu without issues(okay: i found a few minor slowdowns with super mario galaxy) and some switch games behave well.
But really: just about any pc game works fine. I've put a couple dozens of games from itch.io on an sd card and they pretty much all work. Again: a bit finicky to set up (i recommend at least a usb-c - > female usb converter), but it works fine after that.
Other quality of life things: key bindings you just change any game to whatever the fuck you want (okay: wii is a bit an edge case). Epic games and gog have working launchers, so if you've got games there, you can install these as well.
Lastly: yes, Xbox-controlled games are the easiest, but simple mouse driven games or"mobile games"in the steam store work surprisingly good. It can't compare to an actual mouse, but those pads are a solid alternative.
Oh, and it comes with a great carrying case and adapter.
As to disadvantages... It's too bulky for your pockets. It's not exactly cheap(not talking of price/quality), and the smallest version is just a placeholder (what was it? 64 gigs? That's a fucking joke).
As mentioned: the queue goes so fast you might have it this year if you sign up now. Yeah... Still not pick up and get it. They really deserve credit for their way of handling imho, but i can't deny its still a disadvantage in the end.
