One more update on the North Face Goliath ($129 at Campmor).
I slept out in the open (no tent). Temperature was 28 degrees with a wind gusting to 20mph. I had two Link-Rest closed cell foam pads under me.
I was very warm. The chest collar and hood did a good job of keeping the wind out of the bag as I tossed around. I don't sleep on my back. My throat was raw from breathing the cold, dry air.
My sleeping attire is polar fleece pants, knit top, balaclava and good socks. I'm a warm sleeper, i.e. my internal furnace runs pretty good.
So far I think the NF Goliath is a pretty good big-guy bag, but I don't believe it would work at it's 0 degree rating. I think it is an honest 10 degree bag.