Hi Adrianking,
Post #143 here should help you a bit in terms of some better options in the Tampa area.
There are 3 different types or broad categories of “foam” which is polyurethane foam (polyfoam), memory foam (which is based on polyfoam but has very different characteristics), and latex foam. There are a variety of different foams within each of these groups but each of the groups are very different types of foam both in terms of how they perform (including how well they conform to each person’s body and how “hot” they sleep), how durable they are, and how they feel. The iComfort would be considered a memory foam mattress although there are other types of foam in the comfort layers of some of the models. Almost all memory foam mattresses including the iComforts use polyfoam in the support layers but the quality of the polyfoam used in these layers varies widely.
You are also wise to be concerned about the softening of both polyfoam and particularly memory foam which both have a more rapid early softening period which is followed by a more gradual softening which is followed by a “breakdown” process where more serious body impressions can happen. Lower density foams in each category will go through these processes faster than higher density foams. Latex is the most durable of all and goes through these processes much more slowly than the other two categories.
Some of the pros and cons of latex are in this article.
Phoenix