I like the idea of it and I found some great music on prime, but I have to listen to music through my stereo speakers hooked up to my receiver/TV etc. So I have to wait for the Roku app.
I can't listen to music on ear phones and the only other option is some tinny speaker I sometimes use for audio books. Also not useful for me to listen to music too.
I just keep adding stuff to the cloud in anticipation of the Roku app. Otherwise I am out of luck.