I find all the Thermarest pads more comfortable than hard pads such as Ensolite or Ridge Rests. Either I am hard on gear or got lemons, but the first two therma-rests eventually leaked. I admit to carrying one on the outside of my pack while bushwhaking (not a good idea). I sent one back to REI to get repaired- it lasted about 6 months more. The other one was deemed not repairable. I think the newer pads are more reliable. I now use an x-small prolite (8 oz) with a 2x2 foot square of blue foam pad for my feet and my Golite Quest Pack as a pillow base. I have managed to keep this pad from getting damaged for two years of heavy use. This 3-season system is a bit cold and hard when I set up on flat rocks, but fine setting up on dirt or grass. I am on the small side so the x-small works fine. I have not found that getting older makes much difference in comfort.

There seems to be a "just right" amount of air for optimal comfort. If I blow it up too hard it is not comfortable. Often I have to let a bit of air out once I lie down on it.

Also, if you inflate it when it is warm out, it will slightly deflate as the air gets colder. I usually have to add a bit more air just before I get into the tent after the sun goes down. Sometimes I have to add a bit of air in the middle of the night. Although it is a bit tedious, I am much more comfortable if I pay close attention to the amount of air and adjust when needed.