So I get my new modem, good stuff. We call Comcast to get it activated and holy hell, what a pain. We're told that the old one has been deactivated/turned off/whatever and we hook up the new one as instructed. After a while of oddity and confusion they get it to the point where it connects and will load the "activate your shit" page but no further. Trying to activate it in the browser fails and after trying several things and getting only errors, they give up. Someone is scheduled to show up here in the near future to deal with it in person. Fun.
Keep in mind that the modem is fully compatible with Comcast. In fact, it was on a list of approved modems on the Comcast web site. They got the model# of the modem and never questioned that fact, but it's odd how it would be so difficult to get this working correctly. It seems that getting Comcast to do anything over the phone is always a nightmare. I just wish we could call them up, give them the info off the old and new modems and have it done in 10 minutes or so. Clean and easy. If only. I'll post another update after their technician has come and gone.