I don't believe it is how much you download but rather how you do it. I think MWeb want to have the ability to shape you when they need too. Although I rarely notice any shaping if I stay away from torrents and file lockers.
That's what Mweb Guy also says.
I'm just worried (or shouldn't I be?) about the backups I'm pulling from my dedi via ftp, got about 40-odd gigs left to pull before the 26th... coming from OW Gold where it would never have been a problem.