Not entirely surprising, I always suspected that it would suffer a bit from a Not Invented Here syndrome with Logitech, and was always a touch on the expensive side, especially the higher end versions (which is reflected in them only keeping the low end, mono Radio product going in a UE version).
Apparently you can "upgrade" the Squeezebox Radio to the Ultimate Ears version, but this is irreversible, so don't take this route if you may want to go back.
On the plus side, the software has always had strong Open Source support, so that'll probably continue, and possibly benefit from Logitech not releasing new hardware versions from time to time, which required the server to be upgraded to support them. The server may settle into something a bit more long term and stable.