I recently picked up one of the Borah Gear bug bivys, have used it for a few nights with a tarp (Hexamid) and without with the footbox staked out and a couple poles overhead. Very happy with it. With a couple feet of M90 added over the footbox area instead of netting there, and stuff sack, and some cordage for when not using my tarp, it comes in a little under 7 ounces for the large, wide, and side zip version. Remove some of these options and it would likely be in the 5-6 ounce range.
The option for customizations for a low fee was very nice I'll add.