I guess it all depends on what you want to do with that hammock.
If you want to spend a night out of the rain and free of moskitos bites, then a Hennessy hammock is what you need.

Hennessy hammocks are GREAT ! and small and light and easy to pack/unpack (more so if you have the snake skins).
The thermarest mattress I recently bought to take along with my HH is OK except a bit too narrow. I'm now looking for a larger mattress, so when on my back my arms can also rest on the mattress...