"These restrictions were not applicable to all providers because some services, like those offered by Virgin [Media], were not delivered over a copper wire."
Really? What are they making coax out of these days?
Also their sums seem to be wrong
The 10Mb M Virgin service used flat out gives you 14.5 hours at full speed and 9.5 hours at 2.5Mb/s over a 24 hour period. I make that 74GB in 24 hours even the 10Mb L service only gets you an extra half an hour at full speed which takes the total to 76GB.
The Sky service at 7.5Mb/s average as described by Virgin would give you 79GB in 24 hours.
Also since very few people use their Internet at full whack 24 hours a day preferring instead to use it either in the evenings or afternoons I think that a fully working Sky broadband connection is going to be far better than a fully working Virgin connection.