My X1 system is almost unwatchable when I put on certain channels (see below). The screen will freeze intermittently, then it will have moments where it is so patchy that I cannot watch. I have had a technician come out once and he said that the signal strength to my boxes was weak – he speculated there were too many splitters in the walls. This was never an issue before, however, so I would have to assume there is some solution.
The channels that have issues are generally ESPN, NBC Sportsnet, ESPN2, Regional sports and others. My other channels do not normally have issues.