I have had all types of internet services, usually going with whatever is fastest, since it was necessary for my 24x7 support requirements at work. I've done (leaving out the various dinosaur technologies) DSL, cable with Comcast, Cox, Mediacom (current), and FiOS. The only service that ever supplied what they advertised was FiOS. Quite often I got somewhat faster speeds than what I was paying for. I'll tell you, going from the FiOS 30MB service to this Mediacom 10MB-promised/4.5MB-actual service sucked. Especially for the same price. But you get used to it.
"Good judgment comes from experience. Experience comes from bad judgement." - Will Rogers
DW and I - FIREd at 50 (7/06), living off assets