Speed - we have already spoke about the Internet port bottleneck that can occur when a company oversells it's Internet connection, but there is an additional issue that must be addresses. I have been working with networks since 1987. One thing that has changed little is how adding additional users to a network effects the overall network speed. The more workstations one places on a network the more traffic. The more traffic, the slower the network becomes.
Cable networks are nothing more than a local network but on a larger scale.
The more users that are added to this network, the more network traffic. The more traffic, the slower it will become. One might have a 10 MBPS connection to a cable network, but that does not mean they will move 10 MBPS traffic along a network that is overloaded. Cable networks are new, the first one I am aware of was created in Arkansas back in 1994 in Arkadelphia funded by a federal grant, and unlike local networks that have 20 years or more history, cable companies are creating this industry as we speak so there are still plenty of unknowns. Most local ISPs look to a phone service called Digital Subscribers Lines or DSL as a means to compete with cable companies.