I've actually had good luck with Comcast and before that I didn't have too bad of service with AT&T but I have heard of others who have had horrible service with AT&T. Here is the crazy thing. Remember when the Government broke up AT&T because they said they were too big and then broke them up into baby bells only now to have AT&T control all they had before and even more and they are bigger than ever now.
As for my cable/Internet problems I called the Comcast number and did a modem reset or had a modem reset signal sent and that corrected my problem.