I bought a REI Thermal Pro vest from the outlet when it was a deal-of-the-day a while back; the 20% should get it close to that low price. Completely worth it, in my opinion.
My men's medium comes in on my scale at exactly 10.0 oz.
It's definitely a little "overbuilt" with a #5 zipper, elastic banding at the armholes and the pockets. The pockets are simple, do not have zippers and are "floating" (n the jacket's inside, they are sewn on the sides + bottom only so that they make an inner pocket too). I thought about cutting out the pockets, but I actually like having hand-warmer pockets. There's not much to cut, unless you really go to town on the pockets and sew up the pocket opening.
I bought it to take on spring dayhikes, when it there might be rain. I have a synthetic 60g vest (Arc'Teryx Atom) which is VERY nicely made but just not really that warm. The Thermal Pro feels warmer.
One really nice thing about a vest like this is it does not need to be handled carefully the way some ultralight-fabric down & synthetic vests might need to be. I think this is going to be a really useful piece and a great for the price.