Hi sharpshopper,
Since your BMI is 30 or higher there is more information in post #3 here and the posts it links to that would be helpful for those that are in higher weight ranges or have a higher BMI.
While the process of how to choose a mattress would involve the same steps that are listed in the mattress shopping tutorial … most people in higher weight ranges or that have a higher BMI will generally need or prefer firmer mattresses (firmer materials will feel softer because you will sink into them more) and materials and components that are higher quality and more durable than those that are in lower weight or BMI ranges (the materials and components in a mattress will soften and break down faster for those in higher weight ranges than they will for someone that is in a lower weight range that doesn’t compress the mattress as much). I would be particularly cautious about mattresses that use more than “about an inch or so” of memory foam that is less than about 5 lb density or polyfoam that is less than about 2 lb density … particularly in the upper layers of the mattress (which are usually the weakest link in terms of the durability and useful life of a mattress).
Yes … the information you are looking for about the durability of different mattress materials and components is in the durability guidelines that I linked in my last reply. The durability guidelines are also one of the articles that are linked in step 4 of the tutorial.
Phoenix