>>230053>>230055>>230060>>230061This guy knows his stuff.
For me a bivi bag is something like the ME Ultralite Bivi. As climber weight is very important and at 180g for two people this rocks. I never used mine because this comes only out of my pack if shit hits the fan or I have to biby unplanned (Only did this once, not hoping for a second time).
If I plan on staying the night I will use a foam sleeping pad (Thermarest), because they cannot break, a sleeping bag and a waterprove sleeping bag cover if needed. That the kind of bivy that can be fun but most likely one is very keen to get moving in the morning. Plus if the weather turns foul you are... not fucked but it can get ugly fast.
I also do own an Black Diamond Eldorado (pic) for winter but this thing sucks ass in any other application than bivy. If you are cramped in there for days with a partner and have to wait out the rain, better kill yourself. Also this is a single wall tent, so condensation is a given and there isn't enough room for your gear, so this will get wet/snowed one/etc....
For anything than one night I'd use a real double wall tent with an huge vestibule. Because you want to cook somewhere even if it rains and there is the danger of carbon monoxide poissining without enough ventilation. I guess /out/ is all about budget but I say you get for what you pay. So get your self a Hilleberg and be happy for the next 10 years. If you want the "best bivy tent" the Black Diamond Firstlight is 1.3kg for two people. Not waterprove, small but really really light.