Will,<br><br>just out of curiosity I would like to ask you why such a system? I mean it sounds great and it surly does its job but why not a sleeping bag? I'm using a down filled 0 degree bag with the waterproof bivy that weights about 6 lbs and when compressed in the sack it is about the size of the basketball. Like you I'm also climbing so my kit gets different multiple uses. I'm just very much interested why you would go with a setup like yours instead of "pre made" solution. Thanks in advance for your time.<br><br>Matt (who always looks for better ways)<br>