Great discussion in this poll. The OR Alpine Bivy is a perennial favorite, but there are certainly numerous lighter options out there. I still might be able to get a drop for the OR Alpine Bivy, as for many people it could be much lighter than their current bivy. And, I will work to get the lighter bivy sacks here, like the OR Helium and the stuff from Borah Gear and ZPacks. Thanks for voting!
And @Mimosa - thank you for starting another poll with only truly ultralight bivy sacks.