[ThePair]

I have a dual-foam mattress (memory foam over dense standard foam), around 3.5 inches thick or so... I've posted the link to it at Overstock somewhere on the boards. I can close the shells with it and sleeping bags/blankets on the bed, but I found that my back still hurt in the morning... So, for the last outing last year I added an inflatable mattress (5-6" high when inflated) underneath. Much more comfortable, although it obviously reduces "head room" in the back. Deflates completely flat, so I can still close up fine, requires a few minutes of inflating at set-up (an annoyance, but my back thanks me for it!)

I've heard of others that use Sleep Number mattresses, although I'm fairly sure they remove them for close-down. I, personally, wouldn't like that solution, but it's clearly a different matter (and personal choice) for everyone.