I have heard of it but I don't have any experience with it. It doesn't sound as if anyone else who replied has either.
Ask the contractor to give you a comparison of R-factors between this insulation and other types. And do a cost comparison.
As far as being a fire hazard - They probably treat it with a fire retardant - ask about that too. If you have fire blocking, you really have little risk of fire starting or spreading as a result of the insulation. There isn't much oxygen in the wall cavity. (I hope your wiring is safe, though.)
Your best bet really is to ask somewhere else. No offense meant to the other posters, but none of us seem to know anything about the product.