Hi estcstm3,
Unfortunately your experience with a major brand mattress is all too common because the major brands (such as Sealy/Stearns & Foster, Simmons, and Serta) tend to use lower quality materials in their mattresses than most of their smaller competitors that will tend to soften or break down prematurely relative to the price you pay and I would generally suggest avoiding all of them completely (and the major retailers that focus on them) along with any mattress where you aren’t able to find out the type and quality/durability of the materials inside it (see the guidelines here along with post #3 here and post #12 here and post #404 here).
They certainly make some good quality/value options that would be well worth considering but there is more about the 3 most important parts of “value” of a mattress purchase in post #13 here which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability (how well you will sleep), durability (how long you will sleep well), and the overall value of a mattress compared to your other finalists based on suitability, durability, and all the other parts of your personal value equation that are most important to you (including the price of course and the options you have available after a purchase if your choice doesn’t turn out as well as you hoped for).
While I can’t speak to how any mattress will “feel” for someone else because this is too subjective and relative to different body types, sleeping positions, and individual preferences, sensitivities, and circumstances … outside of PPP the most important part of the value of a mattress purchase is durability which is all about how long you will sleep well on a mattress. This is the part of your research that you can’t see or “feel” and assessing the quality/durability and useful life of a mattress depends on knowing the specifics of its construction and the type and quality of the materials inside it regardless of the name of the manufacturer on the label (or how a mattress feels in a showroom or when it is relatively new) so I would always make sure that you find out information listed here so you can compare the materials and components to the quality/durability guidelines here to make sure there are no lower quality materials or weak links in a mattress that would be a cause for concern relative to the durability and useful life of a mattress before making any purchase.
The better options or possibilities I’m aware of in and around the Melbourne, FL area (subject to making sure that any mattress you are considering meets the quality/value guidelines I linked earlier in this reply) are listed in post #4 here.
I’m looking forward to finding out what you end up deciding … and of course any other comments or questions that you may have along the way that I or any of the other more knowledgeable members of the site can help with.
Phoenix