Dave Schultz wrote a review of Therm-a-Rest NeoAir XTherm Sleeping Pad on March 18, 2013
i got the regular size (for when I'm not climbing) and the small (for when I'm climbing). First night (using the small): open bivy at 8k feet, 15 degrees out, no wind, clear skies, 30 degree bag, ropes and ski boot liners for my lower body and I was perfectly warm. pad rolls up into nothing, is so warm you can downgrade your sleeping bag like mad, and go SUPER lightweight for climbing. The sound might bother some people, but who cares when its the warmest, lightest, and most compact pad on the market.