I have a Prolight short. It is bulky to carry, lashed outside a 30 Liter pack.
I have a NeoAir small. I disappears inside a 30 Liter pack.
I have an Exped 7 (with pump) short. It packs very reasonably small inside the 30 Liter pack at the bottom of the pack and under my homemade down sleeping quilt.
I use the ProLight for car camping at the county parks, while traveling.
I like my NeoAir best for "fast-and-light" hiking. I love my Exped for luxurious hiking and camping.
I am mostly a side-sleeper, but, when I am fully relaxed I am a back-sleeper.
The NeoAir seems narrow for me at my shoulders and I am not a "big" woman.
If I have any problem, REI takes it back. I haven't had a problem.
Many stores will take it back, if you have a "leaker". Ask, before you purchase.
Note: I select a good spot to sleep and improve it slightly by removing sharp pointy things.
Plus, I use a Tyvek groundsheet. Rather than sleep on rocks, I hammock. I even use rock-climbing equipment like small chocks to hang the hammock off a rock. My tarp "converts" very nicely into a "travel" hammock.