Price Paid: $100
This bivy sack is awesome and light. It weighs just over a pound. It is waterproof nylon ripstop material with a nylon coated bottom. It has four zippers so you can keep your arms out and still keep you dry. It has a no see um mesh that covers your face for the bugs.
I used the bag in my snow cave in march of 2011 and it kept my bag dry but there was a little precipitation on the sack, but my bag was dry but I guess that's why you use a synthetic bag over a down bag.
Ease of Setup: very easy, plop it on the ground and get in
Weight: 17 oz.
Price Paid: $89
I have been using a TarpTent Virga (2nd gen floorless) and was interested in augmenting my system with a bivy (i.e. extra warmth and moisture protection for my down bag under the tarp tent). However, I was also interested in getting a bivy to be used on its own (i.e. no additional overhead cover).
The REI product is relatively light (but not even close to the lightest out there), is waterproof, but does not provide a "full envelope" coverage as the face area is mesh only (no fabric). The zippers offer lots of versatility, but also add weight. The opening has no drawstring to tighten around your face. So far I am very pleased with ease of entry/ease of use. I find it plenty stuffy enough with the mesh closed, so I can see why REI didn't go the full closure route.
I have used it in moderate weather with a 30 deg down bag. Slight condensation in the foot area, but not much elsewhere (I could have avoided this by changing socks before bed). Quality is good. I have been in it without overhead cover in a light rain. In this scenario, I just chose to stay out in the rain as the bivy kept my bag dry and the rain on my face didn't bother me that much. In fact the mesh actually caught some of it. I didn't even mind the mesh directly on my face.
I can see a lot of use of this product for fall camping without other shelter. If push comes to shove, I plan to put my breathable rain jacket over the top of the bivy for full weather protection (not the most elegant solution, but it should work).
Design: 1 person minimalistic, no pole to keep mesh off face
Ease of Setup: quite easy. Zippers worked fine from inside and outide
Weight: 11 oz
Price Paid: $55 plus tax on sale at REI
I have used this bivy once so far on a three day backpack in the Eastern Sierras around 10,000ft (in July). Due to nice weather predicted, and clear skies I left my tent in the car to lighten my load. Bivy is light, well built, seam sealed and looks nice.
First night was clear and nice sleeping under the stars. I used my TNF Blue Kazoo inside the bivy, a warm hat, and a tent groundcloth. I was quite warm and comfy in the upper 30s. I also used the A16 Insect bivy to keep away mosquitos.
Early second evening, dark clouds came down, and I hurriedly ate my dinner, and moved my ground cloth under some tree shelter. Put my mosquito bivy in place, propped up my hiking poles with rocks. I put my rain jacket as a cover over my face.
It rained for over five hours. I stayed bone dry inside. Just gets you stir crazy, when you cannot really move outside to use the facilities :)
Pros: light weight, well made, kept me dry.
Cons: Face netting stays over the face, and I found it annoying. I did fine using the A16 mosquito bivy (also highly recommended) and my rain jacket.
In the morning, I shook everything, put it out in the sun and dried it before packing onwards.
Ease of Setup: Very Easy
Weight: 1 pound or less
Price Paid: $89
Great bivy. Kept me dry all night. I do have some tiny issues, considering that it was $200 less then the competition it's still a great deal. First, in heavy rain your face gets soaked; I solved this by putting a poncho I found in the Pasatan Wilderness over my face. And if bug net in your face at night bothers you just wear a brimmed hat at night to keep it off your face. This bivy also dries super fast, any rain or condenstaion disappears in minutes.
For those who are considering bivys in general don't use a down bag in them, they pick up the condensation and don't dry out like a synthic bag will. I learned that the hard way.
Design: personal sleep system for mild climates
Ease of Setup: dead simple
Weight: about 25 ounces?
Price Paid: gift
I have used this bivy about 20 times over three years. Day before yesterday, just south of Pinchot Pass in Kings Canyon National Park, the face screen gave up the ghost.
Zipping myself in has always been awkward (37 inch sleeves) and as I did so with my head resting on my synthetic vest as a pillow the screen tore in two parallel places. Duct tape cannot grip it adequately for a repair, and I fear stitching it would only cause a new tear.
June in these moist mountains means gnarly mosquitoes. Mercifully my vest/pillow obscured and plugged the tear zone.
Next night, halfway down the exquisite Sawmill Pass Trail on its final yards next to Hogsback Creek, at substantially lower altitude and much warmer weather, I was forced to use the hot vest/pillow to keep the wretched insects out, sweating for my sins.
REI's inability to match the bivy's fabric and screen's tear strengths more closely has marred an otherwise superb little package.
Prior the foregoing episode I had slept like a baby-never cold, never wet, never harassed by mosquitoes. I grew-up sleeping in bedrolls made from burro hairpads and blankets rolled in canvas. The bivy concept is very close, if only the screen didn't rip.
Ease of Setup: no set-up required
Weight: 17 ozs. Long, 15 ozs. reg.
Price Paid: $99
Overall, I think REI makes some great affordable gear alternatives, but I can't recommend this bivy if you want a breathable waterproof bivy, particularly if you are going to be using it in warm(above 60 Deg)or humid conditions.
While backpacking Zion NP in 10-50 Deg temps on clear crisp nights with a 12" snow cover using a Tyvek ground cloth, Thermarest 3/4 Prolite 3, and Marmot Helium 15 Deg sleeping bag I experienced condensation, moisture, frost and lite ice on top of the bivy as well as between the inside of the bivy and outside of the sleeping bag.
I assume that water vapor from my breath overloaded the capacity for the bivy fabric(REI Elements laminate) to transport the vapor to the outside of the bivy or the vapor froze within/on the fabric resulting in freezing moisture/vapor inside the bivy. I suspect the moisture/condensation would only increase in humid conditions resulting in a sweat-fest if the bivy was zipped up all the way. Perhaps, usable in the right conditions???
Long and roomy enough for my 200 lb. 6'4" med. frame. 17 ozs long, 15 ozs reg.
Design: hiking, climbing, backpacking, snowcaves and igloos
Ease of Setup: no setup
Weight: about 15 ounces
Price Paid: $90
I always leave this bivy in my bag. It helps with condensation build up inside the tent, but it works great outside too. I have used it on mountaineering trips, and it works pretty well. The mesh face is annoying, cuz it can get wet through there, but for 90 bucks, I'm not gonna complain. I found that by using my hard shell around the mesh part of the face, the bivy works great. I wouldn't use it on a big wall, but for anything else, this is the stuff. oh yeh, it's super light. Almost as small and light as my jacket.