I have one on order, so I'm interested to hear responses as well.
As reference, I can state that I spent a couple of nights in the early summer in very similar conditions, but with a snugpak uq (haven't seen a rating for them, but they're pretty thin synthetic, so I would definitely not expect it to be rated as low as 20*F) and a 5*C sleeping bag. I was wearing a layer of Helly Hansen synthetic thermals and a balaclava, no socks or extra layers, and I was almost too warm.
While that was a different uq, it seems to me there must have been something wrong with the way you set it up, or there's a maunfacturing error. Perhaps you could ask someone to have a look at the set-up while you're in the hammock, to see if there's something immediately visible.
Last edited by K0m4; 10-22-2012 at 08:13..