Hi Va.confused,
Just in case you haven’t read it already … the first place to start (and the most important post on the forum) is post #1 here and the information it links to. This will give you the basic information you need (you don’t have to “study” it) to know how to make meaningful comparisons between mattresses, know how to test them more objectively, and to help identify the retailers and manufacturers that have the knowledge and experience to help you make the most suitable and best quality and value choices. it will also help you eliminate most of the worst choices (such as both of the mattresses you are mentioning).
Your experience with the Tempurpedic is valuable because it can help you know the difference between memory foam and other materials (or even different types of memory foam) and which you prefer which is an important part of shopping for a new mattress.
There are many mattresses that have a similar feel and even a similar construction and quality to the Tempurpedic lineup with much better value but you need to know what to look for to find these (or better yet work with more knowledgeable people either locally or online that are “experts” and already know what you would otherwise need to learn).
If you let me know the zip or city where you are I’d be happy to link you to some of the better options or possibilities I’m aware of in your area. if you are comfortable with an online purchase then post #12 here has a list of some of the better online memory foam options I’m aware of (some of whom make mattresses that are comparable in either “feel”, quality, or construction or all three to the Tempurpedic lineup and have much better value). There is also a list of the manufacturing members of this site in post #21 here that specialize in online sales and have some of the best quality, service, and value in the country if you want to broaden your options to materials other than memory foam.
No matter which direction you decide to go in terms of a purchase (local or online) … knowing some basic information about mattresses and materials followed by good local testing with the help and guidance of knowledgeable people are always the first steps.
Phoenix