Hi mike7,
There is some more information about the materials in some of the iComfort mattresses in post #11 here.
You can’t “feel” the quality or durability of the materials in a mattress and lower quality materials can feel just as good as higher quality materials so it’s important to know the quality of the materials so that you have a reasonable expectation that what you are buying will still be suitable in a year or two down the road no matter how it feels in a showroom. It will also allow you to make meaningful comparisons with other mattresses.
Some of the iComfort line uses reasonable quality materials although none of them are good value compared to other mattresses that use similar or better materials.
You can also read a little more about the factors that affect the sleeping temperature of a mattress in post #2 here and in most cases the foams that are used in the mattress are only one part of the temperature regulating picture.
Phoenix