Hi EddieC,
Reading the tutorial post and following the steps there will give you all the information you need about “how” to choose and make meaningful comparisons between different mattresses but the most important parts of the “value” of a mattress are in post #13 here which is really about your personal testing (using the testing guidelines) to make sure a mattress is a good “match” for you in terms of PPP, finding out the specifics of the materials inside (see this article) so you can make sure there are no weak links and compare them with the guidelines here (or post them on the forum and I’d be happy to comment), and then comparing all the other parts of your personal value equation that are most important to you.
Restopedic is a knowledgeable and experienced manufacturer and will also give you good information and guidance about their mattresses.
I would focus more on your own testing and experience than on the technicalities about which type of mattress (or innerspring) is better “in theory”. There is also more about different types of innersprings in this article and in post #10 here but the type of innerspring is only one of many factors (including the overall design of the mattress and the materials that are used over the innerspring) that can make one mattress a better match for some people and not others so I would focus more on your own testing and experience than on “theory” because nobody else can feel what you feel on a mattress.
Phoenix