I recently purchased the Thermarest Ridge, and I've used it once. It was comfortable, especially with the sleeping bag itself adding another layer of protection. I usually start off on my side, then flop over on my back once I'm deep into sleep.

The pad weighs 14 oz. I looked at air mattresses, and there are some good ones out there, but from what I saw they're all in the 2.5 lb range.

The only drawback is that the Thermarest Ridge rolls up bulky. It rolls up into a cylinder shape, about the same size as a sleeping bag in a stuff sack. The Thermarest Z-Lite folds up into a smaller package, according to the manufacturer, so you may want to consider it instead.


Ridge

Z-Lite