has a description of the Spinntex that Mountain Laurel Designs uses. I've been told that Gossamer Gear uses the same kind. It's also the same kind that Thru-Hiker carried. It turns out that the reason GG shelters are out of stock is slow production (sewing) rather than a fabric crisis (source: GG's Facebook page).
I have a Spinntex tent (Gossamer Gear Squall Classic, 2009 model) and have had no trouble with noise. It is rather rattly when you set it up, but once it's pitched tight (easy to do), it's no problem even in a high wind. I did find, though, that the claims that spinntex doesn't stretch as much as silnylon when wet are greatly exaggerated! I have not tested to find out whether the stretching is in the fabric or the guylines, but the tent certainly sags when it starts to rain! Since you can reach the line tensioners from inside your sleeping bag (just unzip the screen door a little and reach out), this is not, IMHO, any kind of a big deal.