User Review: Outdoor Research Alpine Bivy
Design: bivy sack
Ease of Setup: questionable
Weight: 2 pounds
Price Paid: $112
It's weatherproof, no question about it, but its entrance that's one thing I disliked the most, is a bit tricky. If one wants to erect it, using pegs, the string which needs to pass through the sixth anchoring point in the middle of the pole groove is getting on your way while entering the bivy.
Let's think you are under a downpour and are trying to take a shelter inside this bivy, you are soaked wet again while entering the bivy; under such conditions I will just put on my heavy duty poncho and wait till the ferocity of the rain gets down to a manageable state. It must be good on emergency or planned winter outings as long as there is no rain while setting it up or entering to it, snow can be somewhat manageable though. I will try it in snow cave next season. I am sure it will keep me dry.
It's expensive, but you can always find decent ones, just like mine, in ebay.