My hiking partner (Smee) and I have been actively working and testing hammock insulation ideas and systems for over two years. In our experience, the under-quilt is the best answer. Our homemade, down filled models have undergone a fair amount of testing. Our earliest quilts have seen 80 nights of use and 800+ miles of the AT. We are in the final stages of weight reduction and determination of the best overall attachment system. Read simplest, lightest, with adequate durability.
The real questions are:
1. Does the hammock community like the idea of under-quilts?
2. What design features should go into under-quilts?
3. What do you think?