The Winter Bivy was previously known as the Bibler Winter Bivy.
Historic Range: $44.95-$129.95
Reviewers Paid: $99.99
I bought this bag to protect my down sleeping bag in a snow cave. @ the end of the night, there was certainly some condensation inside, but the bag was relatively dry.
I love that it is very light weight and plan on using it as my shelter on an ultralight excursion this summer.
Price Paid: $99.99
Although this is a winter bivy there was no chance of putting my bag in it. -40F would and could not loft. Could barely get in and out due to the ridiculous configuration of the hood. Thank goodness I sent it back and got a bigger bivy or else I would still be trying to get into it. It isn't just the BD bivy, I also tried the REI, Mountain Hardwear, and Sierra Designs - all are not winter bivies but closer to a 3-season option instead of a solo tent.
Settled in on the OR Advanced. Wide enough for the bag and easy to get into to get warm. Would maybe think about it in a pinch for an early-spring late-fall trip with a 20F+ bag where I was in no threat of getting cold while I attempted to get into it.
Ease of Setup: a joke getting into
Weight: light enough for 3 season packing
Price Paid: retail from BD
I bought it for the price and weight and the BD/Bibler name. Very light with ample space for my -40f down bag, however, very difficult to get in and out of due to the positioning of the zipper. Also, zipper constantly gets snagged on fabric as the surrounding fabric has not been stiffened. I had to have my wife help me get the top portion of the bivy over head of sleeping bag and zipped shut. As far as I am concerned a completely worthless design. Buy something else!!!
Ease of Setup: very difficult to get zipped