I have a Roku 2 (the newer faster version) which has a problem when playing music (premium music). About 3 or 4 tracks in, the UI will freeze so that it doesn't update when the track changes. About 5 minutes later, the sound will start to cut in and out before stopping completely. Eventually Plex will quit completely. I am then forced to bounce the Roku as it seems to be really sluggish otherwise.
I have two Roku 2s, they both do this. I also have a Roku Stick and this does it too. So as it stands Plex Music just doesn't work for me.
Serverside, I have a Mac Mini using a wired ethernet connection, core i5, 8GB RAM, SSD.