While those figures are closer to what might work experience with ADSL providers suggests that any limit imposed on a previously unlimited service will send the heaviest users running away even if inside the limits, as many have no clue how much they use, and hate limits with a passion
its not about keeping unprofitable heavy users happy.
Its about doing limits that the infrastructure can handle, if marketing are to choose such limits then there is no point in having them.
Well at least thats my view, obviously with VM it is about marketing.
Ultimately tho if the limits are too high connections will noticebly feel slower and in severe cases stop mainstream apps from working.
As shown with the STM even tho the STM only reduced to previous level of speeds, it had a bad negative impact on the heavy users, those guys are not happy with anything but unlimited so they would still complain with 'any' limit.