I enquired about this service, and was underwhelmed. I watch CNBC on the go, and as a Comcast Xfinity X1 subscriber, I wanted to use the Xfinity Stream app to stream CNBC live on my phone. The people from Xfinity mobile told me that the data used for streaming Xfinity TV on Xfinity mobile would be part of the 20GB throttling limit.
I have been a T-Mobile customer for years. They have something called Binge On. I simply switched my TV service to DirectTV Now. I can watch as much I as I want on phone without the need for Wifi, and the speed is great. Xfinity Stream on a Wifi connection at work was choppy and laggy and the app would stop working. When I called Xfinity support about that, they would give me temporary workarounds after I waited on them on the phone for over 30 minutes after markets were closed - they refused to let me know whether their development team was looking into the issue.
Xfinity doesn't care about customers, and in interviews on CNBC, you see their top management gloat that they are not threatened by streaming services because their customers need high speed internet, and point out that they have a monopoly on that market in large parts of the country. Arrogant people !!