I've read a few threads on this on BPL and some are using it for tarps, many for ground sheets. To me, it's just too fragile and risky for weight savings. Kind of going too far for weight savings, IMO. Shelter is Survival Essential.
For a state park or car camping trip, it's a cheap alternative to a tarp, but I would not trust it for a back packing trip from what I've read. I've never even seen it.