It's a strange product in that it's so fast (at least downstream) that any ISP taking it up is likely to have to invest heavily in their backhaul and peering, yet there isn't the excuse that it's 'only' £40 a month for a gigabit that would allow the sort of overselling that the home providers can get away with. People who pay four figures for installation and over £100 a month are damn well going to use the connection, and complain when it's contended.