I disagree Rick, the radiant reflector in the Neoair is probably not as effective as the "foil". The bubbles provide an air gap, and it's tough enough that it can be used as a ground sheet under your pad. When it's over your pad the reflector is closer to your body, and your sleeping bag will be providing additional air space.

And I fully agree that adding a space blanket over your bag is a good idea too. Your bag is providing the airspace in that instance.

As I've said before, I use bubble foil for a sitting pad too. Based on my experience I don't believe a piece of CCF, no matter how thick it is, will keep you as warm, and it will weigh more per square foot and not pack as well.