We tried it for a couple months, and ended up going back to Xfinity. During the day we would get only around 4Mbps instead of the advertised speeds. The speeds all depend on the congestion of the towers around you, and home internet is prioritized as the lowest.
A friend in another state that also had the service had the same experience as me, and ended up having to go back to Charter due to the unreliability.
It is definitely a beta product and not best for a heavy user