Favorites? Go.

Intended use: Insulation mid-layer for spring and fall camping when it gets chilly to cold at night and want more than just an underarmour layer, but I don't want or need my super warm down poofy jacket, and it's likely to be wet sometimes so I don't want down anyway. Will probably double as a while-hiking insulation midlayer for winter hiking, when I'm being too active to need the down.

Target price range, $100-$150

Target weight range, <8 oz (size Medium), the lower the better

The Montbell Thermawrap UL vest looks just about perfect, but appears to be discontinued and they only have size XL left

The Fratagonia Nano Puff, Deadbird Atom LT, and sNob Face ThermoBall are also open to consideration, but at full price for those I bet I could save some weight for the same price and likely higher quality with a cottage manufacturer. Any of them making synthetic?