[DonC]

Zderf:
I've noticed some slowing while at work but I attribute that to the servers and firewalls. I also have comcast at home and find it to be as fast if not a little more so than ever.
Some of it may have to do with how many subscribers are on the leg that services your home system. The more there are the slower it will be becuase they have to share a fixed band width.
There are a couple of minor settings that can be made on your system that may relieve the problem at home slightly. Do a web search for increasing internet speed. You'll have to wade through the junk but there are some recommendations out the that will help a little.
Also call Comcast and tell them you're slow, they may have some suggestions.
DonC