Massive might not be the right word, but it is above average for sure

I accept that to serial downloaders, like mr_mojo presumably is, 100GB is a trivial amount of data, but it still represents a massive amount for customers on our network.

Once you get rid of the top 1 or 2 % of users who insist on abusing "unlimited" tariffs, the rest of the customer base will have much more modest demands. Afterall, that is the only way that the "unlimited" tariffs can continue to exist -big ISPs know perfectly well that Mr Average does not really use the broadband that much.

if the average is around 15 GB then 100 GB is definitely at the extreme.

If lines test at 1.1 and 0.7 down then sharedband should give you about 1.6 if the asymmetry is set up and handled correctly. About 0.9M up too.