I am also now using the Duck brand shrink film. Best deal.
Seems to work well. I also use a NeoAir, but my NeoAir has one extra level of protection as I sleep with it inside of a TiGoat bivy with a silnylon floor.
I think this stuff works fine as a ground cloth with a NeoAir as long as you do a good job of completely clearing the area of any sticks, pinecones, acorns, pebbles, etc. If that isn't possible, at least put a layer of leaves or pine needles over where you are going to put this.
Because this stuff doesn't breathe at all, expect the underside to be very wet from condensation in the mornings. No big deal as you can shake it out and hang it to dry while you eat breakfast.