I have Blast and it has been working great (very fast - 45-50 Mbps) until December 11th when the modem started rebooting due to time out and then when it finally reconnected speeds were horrible. I noticed that there a few large Comcast trucks in the neighborhood and so I stopeed to talk to them. The technition explained that in order to deal with local conjestion they had switched over to some kind of a "low level" signal configuration but it had introduced a lot of noise and was creating problems.
When it was still broken a few days later I had a technition come out and check the line - when I talked to him he re-confirmed the fact that this was an area level problem and that while the line to my house was fine (as he fully expected) I was going to have to wait until they solved the bigger problem before speeds would come back. Over the last week things were slowly getting better peaking out late last week at about 22 Mbps, which isn't bad but not what I am paying for.
Unfortunately today things dropped off and I'm back to 1-2Mbps.
What I find disturbing is that Comcast made these configuration changes and created the problem and instead if reverting back until they figure it out they just leave us hanging until "they can fix it...."
The other borken part of the process is the complete lack of communication between the local technical team and the Call Center. When I call (and I was told to daily) to report my status and have it documented on my account the Call Center always treats it like a new problem and starts down thier normal script. All I can do is keep wasting my time and Comcast's money by making continious appointments - it is the only way I can keep a focus on the problem and get updates.
Very disappointing.