Hello Bill, I don't know if you are still checking of this thread.
I have read several of your posts and seen your blog. What is this material your have found? I noticed other posts regarding this matter have been completely ignored. If there is a particular reason why you cannot, or are otherwise unwilling to, share this information please make it known so we can stop wondering.
My experience with the GG polycro sheets is that they are great as groundsheets, but very loud and crinkly for most other applications. They are also not very heat resistant; fire burns right through them ( :) ), and the heat from spectra cord rubbing on them is very damaging as well.
Are silnylon seconds inferior in performance. I have heard conflicting answers. Some say it is a cosmetic difference, while others suggest (including RJ) that the silicone impregnation is "uneven" in application. The cost difference can approach 50%.
-------I would wonder how there is such an abundance of seconds of this material, when I see no other material with 2nds offered; there are also few other materials utilizing silicone impregnation.