I've been doing a little research this last week or more. Looking at the ZPacks Hexamid, MLD Patrol and some bivies like the Borah. From what I can come up with is the Hexamid is lighter and cheaper, the Patrol may have a smaller staked out foot print, if it does, that would be nice but with the Borah standard bivy and tent poles comes in at almost a pound without the stakes added in. Any help? I am trying to get around 12 oz total if possible. I know one older than me UL/SUL bper I have done some trips with and he still uses the Gatewood poncho, switching for other shelters now and then, one of which is a 3 oz tarp without a bug bivy, bugs don't mess with him. Must be nice I currently use a TT floorless Squall in the summer at 1.5 lbs., so my friend is my inspiration to go really light.
Edit: I'm thinking of getting a EE cuben quilt, which would eliminate the need for a bivy, cutting out the weight of the bivy, its expense and saving more weight with the cuben material. Maybe that is my bivy solution, was not looking forward to hot nights in the Sierra. All I would need then is a light bug bivy/netting.