I assumed he meant the way they were carried. Obviously, rolled does little good just strapped onto a pack. I use a split NightLite pad, a bit more than $15 to purchase. But, by taping it back together, bumps interlocked, it *fits* into the pad holders of the GG packs and others, generally making the pad and pack a bit more comfortable to carry. (This was mentioned already.) It IS puncture proof. Thorns, sticks, etc do not make it go flat (mentioned). It weighs a bit less than 10oz(~280gram.) Has the same R value as a NeoAir. For sleeping in wooden floored shelters, I far prefer the inflatables, though. They just work better for comfort...on most ground you can shift it around a bit. Depending on my planned route I may cary one or the other or both.
I seem to remember that IR radiation acounts for about 10% of your bodies heat loss. Things like space blankets, etc, don't really do much in comparison to conduction (direct contact) or convection (direct contact with air) heat escape mechanisms. A MAXIMUM of 10% is all you can expect between reflective and non-reflective pads. And, only between you and the ground, or less than 50% of a bodies surface area to start with. This is minor. Two works no better than one.