Agree with 5mile. I have the Down Mat 9, Down Mat 7 and Xtherm. The Down Mat 9 significantly heavier and bulkier than the Xtherm. But exponentially more comfortable. If weight and bulk aren't a big part of the equation, then the Down Mat wins. The Ether Lite isn't even in the conversation if you're looking at cold weather use.I have a Down Mat 9 and an Xtherm. I use the Xtherm for everything up until October, then the Down Mat wins out. The Down Mat is significantly heavier and larger (bulkier).