Fitztravels wrote a review of The North Face Asylum Bivy - 1-Person 3-Season on September 7, 2014
Familiarity: I've put it through the wringer
Footbox venting is really good. Had very little condensation on my bag at the feet when i usually have more in other bivies and even tents
Had plenty of room with a 2" pad to move around.
Technically it only really needs 2 stakes. one at the front and one at the bottom. I usualy attached a line to the head poles and ran it past the front stake to pull the bivy more tight, which made the side walls less droopy. The poles basically provide enough structure to not need stakes in most circumstances on each side.
This can withstand rain for about an hour. Then then next hour it will get slightly worrisome. In the next hour, you will realize you are in a "situation" especially if you have a down bag. One person talked about seam sealing theirs and testing it in their yard, but the problem is that this experiment does not take into effect a live body sleeping inside, breathing and perspiring. My experience is that in a long rain, sure, it was leaking at the seams, but the fabric wet out too. Also, it is nearly impossible in my opinion to not have some part of your sleeping bag touching the side walls, especially if you are side sleeper, in which case your knees and sometimes butt will be touching most of the time (and Im a small guy). This will increase the leaking issue a lot and unless you can lay perfectly still on your back in the same position, your gonna touch the walls at some point.
This bivy also has been weighed by others on reviews (not on this site) and it seems to weigh 4 oz more then advertised. This makes this a pretty heavy non waterproof bivy.
has room at the head for a 38 liter pack and under. perhaps larger but dont know.