I had posted before about Comcast's internet access acting up; see Why Are You So Slow Comcast?. I made the switch last week to Verizon's FiOS service.
I must say that the internet access is a bit quicker even though the rated speeds are the same; I have the 5Mbps download. I am not comparing the upload speeds since they are much different between the two providers. Even my wife noticed the web pages loading faster and email coming down quicker. So far so good.
Two added bonuses as well. The picture quality of FiOS TV is better and I don't even have any fancy HD TVs. Also the phone quality is really good, it sounds better than before and way better than Comcast's "phone" service (you couldn't pay me to use it).
To sum it up if FiOS is an option definitely look into it. I am happy with all three services and it is cheaper than Comcast as well.