I just started using the streaming feature and I love not having a box, BUT...it definitely has some issues.
The biggest one being that when you are fast forwarding or rewinding (LIVE or recorded,) you cannot see the progresssion of frames. So you have no way of knowing when to stop. It's all guess work. The auto resume feature that was available on recorded programs on the DVR was great; would love to see the same feature on streaming, but at least provide the frame progression so you know when to stop.
Also, I cannot scroll all the way to the right to delete a grouping of recordings. This seems to only be an issue on the smart TV; the Roku does have this feature.
The storage space seems to be used up incredibly fast for recordings. The same recordings on the DVR accounted for 49% usage, while on the streaming app it was showing 72%. This seems backwards.
Overall, I like the idea, but I am surprised that with all the streaming technology out there it's a little disappointing to see Xfinity lacking so many of the basics.