A decimal order of magnitude is a factor of 10. And would likely represent a problem.
Really not hard, you don't use the term 'order of magnitude' in binary. Instead opting for 'bit shift', or doubling.
I think avoiding the temptation to false precision is more important. Inconsistent units and the retention of insignificant digits in order to make numbers look bigger (or smaller) drive me up the wall, though.
Not that close, if you ask me.
If you mean something between 5 and 15, you are using base 10. *16 are 4 orders of magnitude in binary, but 1 in decimal.
That said, everybody asking that same question, please, do not use binary orders of magnitude. Our language suffers every time somebody does that.
I'd be surprised to hear someone using binary to talk about bandwidth... Or pretty much anything else.