Forgot to add Stuy, the "up to" argument only really applies to DSL as its rate adaptive dependent upon the distance from the exchange and quality of the line. DOCSIS, euroDOCSIS and DAVIC cable technology all allow users to get very near to their quoted speeds no matter how far away from the UBR they are. The only reason why they get "very" slightly lower then their quoted speeds is due to some network overheads rather then distance and line quality, which is normal for all types of LAN connections.
One major downfall of these cable technologies (okay DOCSIS 3.0 is starting to address this, but the UK is still living in the dark ages on 1.1) is the Upload
speeds are lower, and it only takes a couple of users on the same UBR uploading at full whack to hammer everyone else on that UBR's download speeds.