We love this bivy sack. Amazingly, the Sierra Designs Backcountry Bivy offers a generous full zipper for entry and exit, a separate zippered bug screen, ample space for any sleeping pad, and an attachment point so the bivy can be suspended above your face. All of these features are highly functional and don't break the scale. The Backcountry Bivy was the lightest non-emergency type model we tested. Sierra Designs has also made a frustration-free stuff sack, which is something we hope will be adopted by the rest of the outdoor world very soon!
This product is temporarily out-of-stock, but Sierra Designs assured us that it is coming back into stock sometime in October. If you want this bivy sack, patience will be rewarding!