The issue with the cuben fiber is it's abrasion resistance is low. My zpacks.com cuben-fiber pack got a few holes on just two backpack trips. I used seam sealer to close the holes.
And with a quilt, the fiber is prevents water and air from getting through. So if you try sleeping with it, you're bound to get covered with moisture condensation.
I like my pack, but I think I'd pass on the quilt.
