I have double layer hammocks so I can use a pad, and I often do, but a nice underquilt is very comfortable and allows the hammock to lay normally. There are good threads about the pros and cons of each, but most people who invest in a quilt don't seem to look back. You might check out Just Jeff's Hiking Page, www.tothewoods.net, and look at the pages on hammock camping and staying warm. Lots of other good info too if you haven't checked it out already.