Hi MuseBell,
Some of these design the “feel” of their mattresses to match the Tempurpedic line and one of them designs the actual materials and layering and the feel to match the Tempurpedic lineup as well (and test them side by side with their customers at their bricks and mortar store).
I would talk with each manufacturer you are interested in and ask your specific questions to them. Unless you are very knowledgeable about mattress materials and design … I would also avoid trying to choose a mattress based on specifications that won’t tell you how it feels and performs and will take you down a path of confusion and possible overwhelm. In other words … I would talk with the experts who make and sell the mattresses so you don’t have to become one yourself.
If you are interested in some of the theory behind different designs and layering then the mattresses section of the site has lots more information but I would only scan these rather than try to learn it all when there are already people who know what you would otherwise need to learn. Getting into too much technical information other than as a way to help you recognize who “knows their stuff” can be a recipe for “paralysis by analysis”.
If you talk with the online manufacturers on the list then some of these can tell you which commonly available mattresses (such as Tempurpedic) may feel and perform somewhat similarly to their own and then you can test the roughly comparable mattresses locally to get a sense of what they may feel like.
Some of the better options or possibilities I’m aware of in the Las Vegas area are listed in post #2 here.
Phoenix