Hi sqls,
In general terms … all of the mattresses made by the same manufacturer would be in an equivalent value range. In general … lower budget mattress will also have a slightly lower profit margin than more premium mattresses. I can’t speak to which mattress may fit you best in terms of PPP (Pressure relief, posture and alignment, and Personal preferences) but any of the mattresses made they make would be good quality and value which is why I include them in any of the lists in different areas where they have an outlet. I would avoid the other brands they carry though that they don’t manufacture themselves.
This type of sales environment is never a pleasant experience but at least Lady Americana licensees are usually transparent about the specs of the materials in their mattresses. Of course it’s still important for the retailer to find this information out for their customers who understand it’s importance (and this can be a good test of how knowledgeable and customer focused a retailer really is). As long as you pay attention to the guidelines here (especially #9 and #10) then you are “well armed” to deal with them 
Yes … they make some good quality and value mattresses but once again … they are transparent about the materials they use so you can make more informed choices and meaningful comparisons.
You can read more about which different types of foundations or box springs and which mattresses they tend to be best with in post #2 here. In general it’s best to make sure you test a mattress on a similar base as you will be using at home (either flexing or non flexing) because the foundation or box spring can make a difference in how a mattress feels and performs so if you test on a flexible base and then use the mattress on a non flexing base (or vice versa) what you sleep on may feel and perform differently from what you tested in the store.
Phoenix