I've found that my broadband service through cable is slower lately, too. We're not sure if it's because we use a router to split the service between our two computers, or because of more subscribers in our neighberhood. ------
Possibly neither. Cable companies are notorious for splitting broadband signals at the head end.
There's only one advantage to cable, stealing analog video channels. Most providers are too lazy (and cheap) to add a filter so you can just split the cable and pop the coax into the back of your set and (viola!) you've got cable (or as many channels as your tuner will lock).
Hell, if it wasn't for the fact that I was stealing cable I wouldn't have put up with AT&T for nearly as long as I did.