4 Season Bivy Sack

[polarpop Profile 14er Peak List (5)]

Has anyone used one of these, or just stick with a BD or OR ?

http://military-surplus.us/army-sleeping-bags/Bivy-Sack-Cover-Liner

This military bivy sack was designed to go with the four part Modular Sleeping System (MSS4). This Gore-Tex designed and manufactured bag/liner serves as a ground barrier and a wind breaker. Excellent piece of gear for the serious camper, because it can be used with any sleeping gear of the mummy shape.. Made by Tennier Industries, USA

Unused, never issued genuine military gear. Brand Spankin New or your money back!
100% waterproof, breathable GORE-TEX sealed seams for durability and heat retention.
Zip-down side with snap-over strom flap.
Drawcord cinch at top.
30" X 80", 2.4 lbs.
*Unused item from DoD

[JB99 Profile 14er Peak List (41) 13er Peak List (8)Trip Reports]

Haven't had a chance to use it, yet, but recently received a BD Firstlight from Backcountry (from the link on the home page), and it packs tiny and is in the same weight range as some of the bivies in discussion. The BD is a lot roomier than any bivy and looks like a palace for solo trips. At the same time it won't be too crammed for me, my partner and our dog. Sorry I can't give a more detailed review. I got the BD for winter solo trips to replace my Sierra Designs Baffin bivy that is no more than a sleeping bag cover, really. By the way, I got Backcountry to match some random store's online price of $239 - ask the reps nice and I find they'll often offer nice discounts on Backcountry.com.

[Lewconwell Profile 14er Peak List Not Entered]

I have a Marine Corps Gore-Tex bivy that is similar. It keeps the weather out and breathes well enough with some venting. Not much headroom tho.

[Taillon75 Profile 14er Peak List (40) 13er Peak List (6)Trip Reports]

I have an new OR one. It's great warm and dry all year.

[Alpineair Profile 14er Peak List Not Entered Trip Reports]

I have the Bibler wall and the A-frame. Both have been great. The A-frame works better for me because I can prop myself on one elbow and cook or read. I have room for me and my pack in both.

[SchralpTheGnar Profile 14er Peak List (44) 14ers Skied (41)13er Peak List (15)Trip Reports]

In the winter if I'm going lightweight I like to take two small tarps, and make a floor and a roof. Pros are no condensation, you don't get too hot\sweaty, it's lightweight, and wicked cheap. Cons are that it is not very good in windy snowy conditions, I've woken up with 12" of snow over my sleeping bag, during such times. With that being said, most of the time I just take a tent as I don't mind the weight and I like having roomy shelter since you seem to spend so much time inside of it during winter trips.