I am a former Gossamer Gear designer and the fellow who originally brought Spinn to the outdoor industry (the stuff Gossamer, Thru hiker, MLD, etc. use), so I have a ton of experience with it.I made a bivy sack using spinn as the base and quantum as the top many years ago, and have yet to have any trouble with it. As has been posted above one needs to be careful what you sleep on top of, but as ultralighters (and hikers with basic common sense) my assumption is that we all are. After three seasons I decided to fill my bivy with a bunch of water and hold it up like a water balloon to check out the degradation. Even then there were no leaks, not even pin holes.
You can decide for yourself about noise but it's never kept me from a good nights sleep. Maybe some of those wax type earplugs could be something you could carry on your first couple of outings in case you find the fabric noisy.
I still have a bit of white spinn cloth here if you want to buy some. I can also get you the gray stuff if you want to - I just don't have any here at the moment. $13/yd plus shipping.
Anyway, hope that helps.