I need to get a bivy fot a summer mountaineering trip. I am looking for light as possible. Both of these are around 18oz. I have no experience with bivys. I would think the Rab would be a little more breathable being 3 layer event. However, it does not have a pole to keep the bivy off your face. Is this not a big deal or is it worth getting a bivy with a pole to keep it off your face? Also, the alpine bivy has no bug netting. I have read the OR bivy has a few issues with condensation, but if you vent the opening around 5 inches it helps. It seems that no matter what the material all bivys seem to have condensation issues. Anyway, any feedback would be great.

What's the goal? Region? Expected conditions?

I've got a borah gear m90 bivy. It's windproof, very breathable as it doesn't have a full face covering, and water resistant. If it's going to rain, I bring a tent or tarp.

You could probably stitch a loop above the hood of the rab bivy if doesn't have one. You can string a line from a trekking pole or axe or bit of gear to keep the bivy off your face.

Grand traverse, in Grand Teton National Park. 10 summits in 3 days. End of July. Could be near freezing at night. Daily afternoon. Storms are always possible

If you are in the market for a lightly used bivi sac, I have a Bibler I would sell. It is yellow, constructed from Todd-Tex (Gore-Tex), weighs about 18 oz., and has a zip in mesh insert. The sack came with a plastic hoop in the 'brim' which I removed because it did not work at all. One could use a piece of stiff wire to shape the brim, but I simply would put my pack inside above my head to raise the fabric off my face. I am thinking about $80 shipped.

Email Daniel-p-smith@hotmail.com if interested.

bivys are like coffins. it sucks your positive mood and energy.. if I were you I would consider a light solo tent. If it was a 1 day hike/climbing, I would say "go for it", but considering you will spend at least 3 days and more than 12 hours a day in a bag! you will feel depressed.

couple years ago I had a ferrino bivy hl (semi bivy/semi tent) and once I had to spend more than 2 days in it, god it was like I was trapped inside, eventually I cancelled the expedition and returned home.

In a tent, you can sit, you can cook, you can read/write, stretch your body, you can pee.. in my opinion, bivy's are appropriate for fast climbing and emergency situations.