My house at college has Comcast Cable. It is very fast, when it works. We constantly loose out internet. Comcast has come and checked out connections, but they find nothing wrong. At my last house, it worked perfect. This year, we loose internet probably 2 hours a day. I can't comment anymore than that.
At my home-home, we had Verizon DSL. Not as speedy as Comcast, but it always worked and never lost the internet. We recently switched to FIOS, but I haven't been home yet to test it. My father who is just slightly more advanced than the average computer user managed to connect both our power mac and PC to the internet. He is very happy about the speed. I asked him if he every loses the internet and he said no. I'm going home for the holidays tomorrow. I can't wait to play with it. I'll report back later.