I will weigh in a little. Im a little bias, but i will try to stay as objective as possible. I work for Comcast, have a related degree in the field, and will be getting my masters in telecommunications engineering hopefully sooner than later. With all that said, the difference is 99% marketing.
Someone mentioned something about customer service earlier and several people mentioned pricing. Thats what its all about. If your happy with your monthly bill and customer service stay with your provider. Prices are almost exactly the same without promotions, they are simply bundled in different ways to appeal to demographics which can make one seem cheaper than the other.
The funniest thing i reguarly get asked is “So, when are you guys getting fiber like verizon?” We have had fiber in New Castle County since 1996. The infrastructure we use is called FTTF(fiber to the feeder) as opposed to FTTH(fiber to the home) which is Verizon’s infrastructure. I dont want to bore anyone with technical details, but for all intents and purposes they are nearly identical as it relates to the consumer. The common “if more people have comcast you service is slower” is a half truth and something that effects verizon equally. Its a capacity issue that is directly related to the load balancing at our hubsites(phone central offices) and has little to do with our infrastructure. Also, speed tiers and the amount of throughput that a provider can offer to a customer is also directly affected by capacity. With that said, a startup company with 0 highspeed internet customers can offer larger speedtiers and more affordable rates. As their marketshare increases, so will the damand for bandwidth.
People have different experiences. One bad experience can make a lasting impression. The one thing i will say is if both services are installed correctly and the rates, or speed tiers provisioned to the account are comprable, the speeds experienced by the customer will be comprable. Neither service is superior. A network is only as strong as its weakest link, and unitl your set top box or computer begins to interface with fiber, your still relying on copper throughout your house. It makes very little difference that fiber comes 300 yards closer to your home, your still using copper. And for those that feel that verizon has better picture quality, it makes me laugh every time. Nothing is true digital. TV only uses a digital modulation scheme, but the carrier is still analog. Same thing with your modem. Its called a modem because it (modulates/demodulates) the signal is still analog, baseband, but analog. Most of the time competing internet and cable providers use the exact same vendors. Same switches, modulators, routers, etc etc.
Like i said before, if you like your service and your happy with your bill, stay where your at. The grass isnt greener on the other side. However, if you change to Comcast i will come out and sweep, balance, and optimize your node for you Saint:)