I don't know anything about it, but this down bag with 4" of loft is on sale for $99.00.

Anyone use it?

http://www.luxurylite.com/bagindex.html

I bought one, but haven't had a chance to test it. I bought a couple of the Luxurylite bags that had some underfilled chambers, and they've been good into the upper 20s with a fleece jacket and base layer. I filled the chambers on one of them with 800 down, and was almost too hot at 20 degrees.