there's another posting about suddenlink and overall ISP's here.
Our experience in Oak Hollow with ATT was good, then suddenly it went bad, they said they didn't see a problem, we switched to Suddenlink, and it was good until we moved away.
I'm no techie, but Internet speed seems to be closely related to neighborhoods, but I have no idea why.
Check out the Tara Farms blog because there seems to be a real issue there.