If you'd like a different perspective regarding the quality of your broadband connection and the reasons for congestion this is a good read that basically says ATT at least does not provide enough connectivity from the Level 3's optical backbone to their regional networks. I suspect Verizon is probably the same.

http://blog.level3.com/global-connectivity/chicken-game-play...

Here's a letter Level3 wrote to ATT on the subject [pdf]. http://www.level3.com/~/media/Assets/legal/cicconi.pdf