I bought a bivy.
I went to the Bloomington REI. It was huge, as it is the 3d largest REI in the country. The store is one building, but the sections of the store (camping, men's clothing) are partitioned off in a way that it can be hard to navigate.
In the store, they had a few choices: ID Bugaboo, Bibler Tripod, SD Sangori and the OR Alpine. I went with the Alpine. Here's why.
First, I looked at the ID. It did not have hoop on it; this would allow snow to press down on my face. It would be great for summer, but not great for winter snow. It did have a nice hood and vent, though. ID makes a bivy similar to the Alpine, discussed below, but it was $310, and for that price, I would have gotten a tent. The weight savings was minimal and I'm not sure on durability issues.
If I end up getting a bivy for summer use, I believe it will be the Ptarmigan bivy from Titanium goat. It weighs 6 oz and it would compliment a 5x9 tarp nicely.
Second, I looked at the Bibler tripod. This is the same pole design/dimensions as the BD lightsabre, so it was more bang for my buck. And they didn't have the Lightsabre in stock. Anywho, the hoop pole on the Tripod is not a hoop pole, but instead, is two straight poles connected by a pre-bend (about ~120 degrees). I have seen these before in an older Marmot tent, and the owner of that tent has to replace the prebend every two or three seasons. What happens is this: The upright poles insert into each end of the prebend (which is about 4 inches long, btw). However, the poles need to be secure and stay secure in the prebend, otherwise there is a gap. This gap weakens the connection and bends the upright and the prebend. I'd rather not deal with that. Also, the bibler was out of my price range and weighed more than I wanted it to. For that price, I would have gone with the BD Firstlight (on sale for $209 + shipping @ backcountry.com)
Third, I looked at the OR Alpine bivy. It is made with 3-layer Gore-Tex. This Gore-Tex is Labeled "Respiration" because it is designed to let oxygen and carbon dioxide molecules through the laminate. It is the same fabric as the OR Aurura bivy, discussed in a previous post.
The bivy has a single pole, a flimsy four or five section pole that is shock corded. It slides into a sleeve that creates the hoop.It also has a bug netting option. This way, I could push the hoop down on top of the fabric and another hoop comes up that supports the bug netting. This hoop is made of a flexible wire that seems foldable and malleable for packing. I'm curious as to how long it will last.
Again, the bivy only zips open to shoulder length. However, I could get in and out very easy. I also believe I could set this bivy up very easily if it was snowing and keep plenty of snow out.
The bivy also has sleeping pad straps in it. They are a patented design, but my first impressions are that they are superfluous. They might add an ounce or two, so I don't plan on cutting them offf. It just isn't worth it.
Anywho, I will be sleeping outside tonight, so I'll report back with the test later.
Ona side note, I returned my REI Alpine lakes full zip pants. The choice was simple really. A weekend or two ago, I spilled water on them. I stayed dry, but the fabric absorbed the water, much like the outer shell of a cordura fabric would. Well crap, I thought, I can't have that.
The shell fabric, although there is REI's proprietary wp/b fabric in there, is not like rain coat fabric, but it is more robust and seems to be more abrasion resistant.
The pants were fine in snow, and they breathed exceptionally well. The full zips were nice for venting and putting on w/o taking off my boots. This was a great feature in the morning. However, they just had to go. If I were walking around on a slushy day and got the pants wet, they would undoubtedly freeze if the temp dipped below freezing at night.