Hi Hoffman,
Welcome to the Mattress Forum! :). As you know I think very highly of Jeff (which is why he is one of the members here) and he is certainly doing a great job helping to educate consumers about mattresses and the industry in general.
The manufacturer is the name of the company that makes the mattress and some manufacturers make several different “brands” (just like General Motors makes Chevrolet, Buick, Cadillac, etc). You can see some of the different brands that Therapedic makes on their (website here). Either way I would be very cautious about choosing a mattress based on the name of the manufacturer or brand name on the label. The problem with “brand shopping” is that you aren’t buying the brand … you are buying a specific mattress … and most manufacturers make a wide range of mattresses that can vary from very low quality that in some cases may only last you for weeks or months to much more premium mattresses that use higher quality and more durable materials that will have a much longer useable life. In terms of quality and durability … a mattress is only as good as the type and quality/durability of the materials and components inside it regardless of the name of the manufacturer on the label or the price of the mattress. The name of the manufacturer on the label or the price of the mattress won’t tell you anything about whether a specific mattress is suitable for you in terms of PPP or whether there are any lower quality materials or weak links in the design. There is more about the risks of brand shopping in post #5 here and post #12 here).
Just in case you haven’t read it yet … the first place I would start your research is the mattress shopping tutorial here which has all the basic information, steps, and guidelines that you will need to make the best possible choice … and perhaps more importantly know how and why to avoid the worst ones regardless of the name of the manufacturer on the label.
One of the most important links in the tutorial is post #13 here about the three most important parts of the “value” of a mattress purchase that can help you make more meaningful comparisons between mattresses in terms of suitability, durability, and “value”.
Therapedic makes many different mattresses so it would depend on which of their mattresses you are considering and the specifics of the mattress you are comparing it to. There are dozens of manufacturers across the country that make mattresses that use good quality and durable materials but you would need to compare them on a “mattress by mattress” basis based on how suitable they are for you in terms of PPP, the durability of the materials, and all the other parts of your personal value equation that are most important to you. There is more about the different ways that one mattress can “match” another one in post #9 here but the only reliable way to know way to know whether one specific mattress is similar to another one in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) is based on your own careful testing and experience and the only way to compare the durability of two mattresses is by comparing the specifics of the type and quality of the materials and components inside them.
I would generally suggest comparing all the mattresses you are considering against a common set of criteria rather than trying to “match” mattresses you try against any specific mattress which may not necessarily be the best “match” for you.
The better options or “possibilities” I’m aware of in and around the Greenville, SC area (subject to the quality/value guidelines I linked earlier) are listed in post #2 here.
There is more information in the first part of post #2 here about some of the different ways that can help accommodate a couple that have very different needs and preferences but your own careful testing on a mattress (with both of you on the mattress and hopefully using the testing guidelines in the tutorial) will be the most reliable way to know which mattress or “sleeping system” is the best match for both of you. If you only add a topper to one side of the bed then it will be raised higher than the other side and there would be a ridge in the middle that would be very noticeable for most people. I would generally stick with a mattress or sleeping system that is either a good match for both of you or where each side of the mattress was a different firmness but is the same height.
I would always keep in mind that the knowledge, experience, transparency, and guidance of a good retailer or factory direct manufacturer can be one of the most important parts of a successful mattress purchase because they will already know what you would otherwise need to learn. They will also know the specifics of their mattresses better than anyone and in combination with your own testing and feedback will be your best source of guidance about which of their mattress will have the best chance of success.
Phoenix