im also a heavy user, never been in there top ten mind you, or had a warning letter so far, but can do a lot a month each way
im now on 120mb, was on 100mb, wouldn't change for anything tbh, price is great, have all four services from them, tv basic, home line basic, mobile £12 a month for a great phone and deal for gf then 120mb BB, won't print price as it may make you sick/mad

but a great deal, been with them since day one, was NTL user from when they first started, get loyal bonus, DD bonus, and pay phone line rental up front to get a discount on that as well, all good savings making my monthly bill dirt cheap
you can keep your BT fiber, our area is getting it now, but costs a bomb, VM is doing a trial now in london for 200mb, so roll on christmas when we should get it
speedtestnet results
122.80 down and 11.35 up, which is about average,can be better depending on time of day, never goes below 100 down or 10 up, had the new cat what ever cable done as well to box for faster speeds and new hub, which is as stable as hell and so fast for wireless, not that i use it mind you, i'm cabled in the whole house.