i've used this stuff. It was pretty soft, but wouldn't take much detail. When it dried, it was still somewhat soft. I used it to make quills for a Predator mask. Once it was "dry", I tried bending a piece to see how far it would bend before breaking.
It didn't take much.
If you are looking to use this to replace super sculpy or aves epoxy putty, don't.
If you are looking for a cheap material to sculpt out of, but don't want sculpy or aves, try Celluclay. It acts much like clay but is made out of finely shredded paper and volcanic ash. Beware, it shrinks, and can crack if you use to much water to thin it out.