You know first of all, aside from the gigantic costs involved in generating one coin, this form of investment only appeals to those interested in turning one buck into two as Bitcoins only purpose is to perpetuate itself, thus all those interested in "responsible" or "green" investments or a product or company they believe in are all ruled out, furthermore, how one actually converts ones coins into hard currency is often cryptic to say the least (maybe that's what they mean by Cryptocurrency) unless someone will allow you to pay for their products with them which are equally few and far between if not downright shady. So I would award it an investment rating of "Three Legged Donkey".