Hi Sdot,
Unfortunately the specs you listed don’t include the quality of the foam … only the type.
Simmons and other major manufacturers typically use fairly low quality foams in their mattresses which will soften and break down much more quickly than higher quality materials and it’s never a good idea to buy a mattress where there is no way to find out the quality of the materials that are inside it. Lack of disclosure almost always goes hand in hand with lower quality materials and Simmons is no exception. A mattress will soften and break down from the top down and if there is more than around an inch or so of lower quality materials in the upper layers then this would be what I call the “weak link” of the mattress and I would tend to avoid it (this mattress has over 4" of suspect materials in the top layers). You can see an example from one of the forum members here that purchased a Simmons from Grand Home Furnishings and some of my comments in this thread.
If you let me know the city or zip you live I’d be happy to let you know of any of the better options or possibilities I’m aware of in your area.
In case you haven’t read it yet … post #1 here has all the basic information, steps, and guidelines that can help you make the best possible choices.
Phoenix