Hi HurricaneBob,
This would have been the firmest model they offered at the time and while it may have been a little on the firm side even at the time … it may have been “just in your range” of pressure relief. Over time our needs can change and as the top layer of memory foam softened … you may not be 'going through" it more and feeling more of the firm layers below the memory foam (in other words it isn’t “cushioning” you as much).
The original Tempurpedics and other memory foam mattresses of the time slept hotter but technology has advanced and while memory foam in general is still more of an “in the mattress” feeling and can act as an insulator more than other more breathable forms (suchas polyfoam or latex) … they are also generally more breathable and cooler as a grooup than they were. There are also other elements that can contribute to the temperature regulation of a mattress which includes the cover and any quilting, the mattress protector used, and the types of sheets and bedding that you use.
In general, natural fibers are more breathable and temperature regulating than synthetics and a wool or stretch cotton mattress protector can also make a difference over the breathable/waterproof membrane types which are breathable but not to the same degree as natural fibers. With wool for example … you have a water resistant layer that is very temperature regulating but it is also a little thicker and may have a bigger effect on the feel of the mattress. Everything is a tradeoff. Some of the ways that are being used to cool down a memory foam mattress for those who like the feel of slow response materials are in post #6 here.
The most effective way to find your best mattress is to follow the steps in post #10 here.
Finding the better local manufacturers or sleep shops in your area that have the knowledge to help you make your best choices for your needs and preferences (including temperature regulation) and that make or sellhigh quality mattresses with good value can be a more important first step than trying to find a good mattress but not knowing where to go or who to believe.
If you let me know your zip or city … I’d be happy to let you know of any better outlets or possibilities I know of in your area.
Phoenix