Through 1.5.6 Studio would “freeze” or crash after awhile, perhaps a half hour, streaming via UPnP. (Direct connection has not given any problems.) With 1.5.7, playback via UPnP has continued just fine for quite a while. I intentionally left Studio on with the music stopped and set to UPnP for an hour or so between listening sessions, just as a further test, and afterward when I selected music with the remote and pressed Play, playback began again without incident.
Sound quality remains wonderful.