I tried a Tempurpedic memory foam mattress and found it to have several problems:
- It takes a few minutes for the foam to form to your shape. Until then it feels kinda hard.
- After it has formed to your shape, it doesn't want to change. So, if you roll over, you end up with this depression that tries to make you roll back into it. This lasts for at least a few minutes, till the foam reshapes. Then it happens again the next time you move at all.
- They tell you that once the foam forms to your body then you feel no pressure points. That is BS. It is impossible to remain perfectly still. Any movement you make causes you to feel pressure as the foam does not adjust quickly enough (see above).
- While I did not find it too hot, it does not allow moisture to flow well, so it is very sweaty. Which then causes me to get cold in the middle of the night if the covers slip and let even a little bit of draft in underneath.
Here is what I have found to be the most comfortable mattress I have ever slept on: I use a Coleman air mattress with a 2" layer of thinner, softer memory foam that I got at CostCo. I think they still carry it. That foam has holes in it so it is more breathable. If I have too much blanket or my blankets do not breath well, then I can still get a little sweaty due to the air mattress not being very breathable (duh). But otherwise it is insanely comfortable. I can adjust the Coleman mattress to just the right pressure and it has stayed exactly the same for over a year.
My current mattress is 39" wide, but I have done some research and Coleman makes an air mattress that is only about 4" thick and 20" wide. This is perfect for use in a van or a smaller RV. After several years of sleeping with my most recent (and hopefully last) ex, I got used to sleeping in a space only about 18" wide (on a queen bed). Just cut some foam down to size and you will be in heaven.