Neil,
Don't hold your breath for 8mb download its a fable Bt use asdl and the distance from the exchange and the quality of the line are a major factor in the download speed that you get .I do not know any one who gets an 8mb download.
I have BT top package No 4 and after 1 month my top download speed is max 4 mb. And that is on a good day normally 2.5 3.5 mb download.
Don't get me wrong I like the system great international call rates too only 1.2 pence per min to Newzealand. Also have the any time free up to 1 hour on any 01 or 02 number But 8mb is myth.
As stated still happy with the package