I think only Cabletel areas had remote subscriber concentrators at hubsites as far as I know. Nynex, Videotron & Bell Cable never adopted this method believing it was unneccesary with high capacity fibres.
Of course you have to remember that BT still has the majority of fixed line customers. Their exchange capacities are similar as they use the same types in a lot of cases. Ntl have about 100 switches, BT probably 10 times that.
