Good kit, but needs a little improv.
I bought this and finally had a chance to give it a test while camping at Solar Fest this weekend. Generally I am happy with it. It's super light weight, affordable, it took me less than three minutes to set it up, and just as little time to pack it up when it came time to roll out.
As others have mentioned, the Pertex barrier is indeed waterproof...both ways. The plus side of that is that if it rains, you're dry...from the outside. But condensation is a mild annoyance. I tried both zipping the shell completely -- which lead to condensation from my breath and sweat -- and leaving the bug mesh open -- which lead to atmospheric condensation when the dew settled. I say it was a mild annoyance because I was also using a Marmot 40 degree minimalist bag, which easily absorbed, wicked and dried the condensation before it ever reached my skin. In summer conditions this makes it only a problem if you are unfortunate enough to roll over in the middle of the night and touch the bivy, as it's a bit like being brushed with a cold, dead fish.
I do suspect, though, that in winter that condensation might be a problem as any sort of moisture could lead to compromising, dangerous loss of temperature.
My only other negative on this one is that if you're looking to keep the bug net open but the flap unzipped, there's no easy built in mechanism to keep the flap from falling over the bug net. I fixed this on the fly by applying some sticky velcro to the bag on the area over the hoop, and on the flap. That works for drying it out during the day, and at night...if you don't mind that whole dew condensation thing. A better solution for sleeping was to zip the bug net, then stand my Koppen trekking pole -- at it's shortest height -- at the head of the bag. After the bug net was sealed I was able to hook the flap over the pole, giving some shelter above the bug net. You could also set up a tarp vestibule using the same concept, but since there's a built-in solution why go the extra mile?
Please don't get me wrong...this is actually a good bivy. I had read that the condensation issue was a given and bought this knowing that. The fixes above were super simple. Down the road I may upgrade and get a different one-man camping solution, but this isn't a bad start. And when I do upgrade this will go into my bike pack, as it's a handy piece of kit to have as a back up solution.