[praxulus]

I would much prefer an explicit data cap known ahead of time to random unexpected throttling.

[wtallis]

It's not a binary choice. The throttling at the point of congestion is unavoidable (though the ISP can choose to be more or less fair about this throttling). The monthly cap is optional.

[kixiQu]

Unfortunately, with the former, you still really get both, since everyone starts the month uncapped...