I have some Hennessy hammocks and they're nice hammocks that work reasonably well; except the rain fly isn't the best design, nor is it a four season setup without an under quilt. It also can't be set up as a ground shelter. But other than all that, they are a good value and very comfortable to sleep in and backed from a good company that stands by their product. Once you get over the thought of being a 'bear burrito' you'll never want to go back to sleeping on the ground again.
I decided for now not to buy or build a under guilt or get a replacement rain fly (there are several reputedly good makers) for my Hennessy's. In stead, I bought a Clark NX-250 and have been reasonably well satisfied so far.
http://www.junglehammock.com/models/nx250/index.php
That is one fancy, nice hammock. I'd love to have one, but $430 is a little to steep for me. If you come to the get together, I would like to check it out.