I have contacted Xfinity support at least 5 times to complain about screen freezing and delays, especially unbearable during sports broadcasts. The interruptions and delays make it impossible to enjoy the broadcasts. One technical support agent suggested I switch to the slower 2.4 network channel and also said that if I upgraded to the 1 GB speed the problem would be solved. However, the problem persisted and I subsequently cancelled the speed upgrade and its higher cost. Another tech support person suggested I exchange my white tower modem for a more recent model. I have not yet done that but am very skeptical about that fixing the problem. I think Comcast's strategy is to make streaming increasingly problematic to force customers back to their dreadful cable TV packages.
Recommendation: When it comes to Comcast lower your satisfaction expectations.