Used a thermarest guide for years. But going UL and 4-season required this. Perfect down to 22F so far under a tarp with tyvex ground cover. Pack the blow up bag unless you like passing out inflating this saweet piece of kit up, plus it doubles as a stuff sack for your sleeping bag. Tip: don't overinflated.
This review was written in the old system and had content requirements that are different than reviews written today.