love this bag. i havent used it in temps lower than 20 degrees as of yet, but the last time i used it, i was in the catskills and temps dropped down to the low 20's. it began to snow. i was using the bag in a lean-to with a thermarest scout sleeping pad, and a SOL thermolite 2.0 bivy. i woke up in the middle of the night at one point wet with sweat. looking forward to further testing but this year has been a pretty mild winter in the northeast. for the price, this bag is pretty unbeatable in my opinion. ill update further if i have any more issues.