Are these the only clear materials for soft enclosures? What are the pros and cons of what's available?? Relative costs? Do most use 40 mil thickness? I upgraded with Strataglass and it's sure clearer than plain old vinyl, but I never got a clear understanding of how it compares to other products. By buttoning to the underside of roofs when open it's fast and easy to open and close and avoids scratching the material.