When I was young I slept on the ground, then moved up to a blue foam pad. That thing was warm, and cheap, but not much more comfortable than the ground.

Then I bought a Thermarest. That was much better and I used it for years - I still have it 26 years later and it still holds air.

As I got older even the Thermarest wasn't good enough. I'd wake up every morning about 4:00 am with an aching back, which would hurt until I got up (at 7:00? 8:00?) Once I was up the hurt went away, but came back again the next night.

So I looked around and found the Big Agnes Insulated Air Core air mattress. It's XL and coffin-shaped. It's much more comfortable than the Thermarest. It only takes 2 minutes to blow up (and I do it in a relaxed way - just slow breaths. It's almost calming.) It's as light as my Thermarest, packs up much smaller, and I've used it for three long tours with no leaks. I don't think it's quite as warm as a Thermarest, but I mostly tour in summer. On a spring tour to Zion Canyon last year the temperature got down to freezing and I was cold! I don't know how much of it was attributable to my air mattress, and how much to my old, worn-out sleeping bag, however.

However, one of these days I'm sure I'm going to spring for one of those NeoAir's by Thermarest. I've heard so many great reviews. They're expensive, but comfort is worth it to me.

P. S. The inflation that works best for me is to blow it up, lay on it, and release air slowly until my first body part barely contacts the ground. (I have to wiggle a little to see if it's actually touching.) This works better for me than a firm, highly-inflated mattress. But everyone's different. We have a Sleep Number bed, and my wife's side is about twice as firm as mine.