That's a bit slower than I get on my DSL connection Halo, but sounds pretty realistic, given the aggregate bandwidth available over the Internet. Last mile starts becoming a non-issue once you get above about 1Mb/s as the Internet is the bottleneck then.
Comcast is our local cable too Halo.
Routing is somewhat controlled by the ISP. It depends on the number of pipes and connections the ISP has.
Cable networks are laid out much like AOL, where they have Internet connections spread throughout the country and each WAN covers a large regional area. It is not unusual to see 6 or 7 hops in a trace inside the cable network before reaching an Internet gateway router.
DSL providers tend to be more localized, except for the very large DSL providers, which use a network topology much like Cable.
Normally you will have fewer hops with DSL than Cable, but not always. Again, the ISP is the key to that.