You can stream from your own library or whatever streaming service you like all through one system and app. I have local files, Spotify, Bandcamp, and Qobuz accounts as sources and they’re all treated as equal citizens. Personally I much prefer “owning” the music, but I take your point about discovery.
I use it and find it really good. I have it running in a Docker container on my media server rather than a HomeAssistant add-on.
The interface is a bit clunky, but that’s my only real complaint. There are some third party apps available that ease the pain of this a bit - I use Ensemble on Android.
The main strength is the ease with which you can add multiple different sources and have them work side by side. I do get some duplication, but that’s usually because the Spotify version of an album is the deluxe or something along those lines.
HomeAssistant integration is great. You can easily automate playing tracks/albums/playlists - I have a wireless button under the kitchen table that triggers my choice of playlist on a double press and my wife’s on a single press.
Sendspin is fantastic - it’s practically effortless to have multiple players with different protocols playing in sync. Really looking forward to this protocol developing more, since the unfinished version is so good!
I’ve got one of the original models. I just have it set up with the TRMNL cloud version at the moment and it’s pretty cool, but there is a setup where you can run a HA add-on to mirror a dashboard to the screen. I would miss my imprecise literature clock though…