I think xfinity stream on the Roku device could really be a great app - eventually. I do have a few suggestions for improvements though:
I moved your thread to the stream app area of the forum.
There are 2 big improvements Xfinity could make on the Xfinity Stream Beta app:
1. The ability to replay and rewind live TV. Hulu Live capability is the best in that you can even start most live programs from the beginning.
2. Go to last channel watched when you select back.