I have just returned from a week in the Boundary Waters with a Hennessey Explorer (freaking awesome trip). I've had the Hennessey for a couple of years now but this is the longest hang I've done although not the coldest. However! I used a ThemaRest bag with a NeoAir pad for the first time. With the pad in, and this is true with other pads also not just the NeoAir, I couldn't lie on the angle that an Asym is designed for and had to sleep in the banana position. Although I still slept well compared to my friend in the tent, it just wasn't what I wanted and it was cold enough that I definitely couldn't do without the pad. So now I'm considering an underquilt and not having much luck matching up with the HH although there are a couple of possibilities. I am leaning toward the full-length. I want warm feet and I just can't see that happening with a 3/4 without dragging along more components or special clothing. Any comments on one vs. the other?