Hi susanco,
I’m certainly happy to speak to the quality of the materials in any mattress but the only way to make comfort or design choices is your own personal testing and experience or more detailed conversations with a manufacturer (see mattress firmness/comfort levels in post #2 here).
I haven’t come across any “inept” customer service people there but I’m not sure what you are looking to find out. It’s possible that you are asking questions that have more subjective than objective answers where it isn’t possible for anyone to answer your questions with the degree of specificity you may be looking for which may be part of your frustration.
Some of their memory foam mattresses have a rough “equivalent” in the Tempurpedic line (such as the Cool Series) so you could use the equivalent Tempurpedics as an approximation for what it feels like. Any of their customer service people will tell you which of the Tempurpedic mattresses are roughly equivalent (for the models that have a rough equivalent in the Tempurpedic lineup).
Most of the rest of their lineup have exchangeable layers so that you can exchange a layer (or in some cases one of two layers) if your choice is less than ideal. Only the Cool Series mattresses have free returns though. The others would be more costly to return because they would require truck freight that isn’t covered in the return policy but a layer or layers can be exchanged in many of them which is how they can be fine tuned to your preferences without having to return the entire mattress and a layer exchange is a low cost option for find tuning your mattress.
Terms like “soft” and “firm” are very subjective and relative to each person’s perceptions so in most cases they can tell you which of their mattresses would be firmer or softer than another one they have (or describe firmer or softer comfort choices with their mattresses that have comfort options) but each person’s body type, sleeping positions, and individual perceptions and preferences can mean their sense of what is soft or firm can be very different (see post #15 here). A manufacturer can only go by the “averages” of other people and provide you with information about what most or their customers will feel but this may not be accurate for any individual that is outside these averages. I think in a lot of cases consumers may believe that a retailer or manufacturer can predict what one of their customers will feel on a mattress and the customer may get frustrated when they can’t because only your own experience can know this with certainty.
I doubt that any of their mattresses including the firmest versions are anything like “sleeping on the floor” and I wouldn’t pay much attention to reviews of other people who may have very different perceptions or definitions of soft and firm than you do (see post #13 here about reviews)
This is very true with a finished mattress and it’s always wiser to choose a little firmer rather than a little softer if you are in doubt because you have many more options (either with a layer exchange or a topper). With mattresses that offer a layer exchange though it’s also possible to choose a firmer layer if the one you have is too soft and this is one of the advantages of exchangeable layers.
I’m not quite clear on what you are asking specifically so hopefully this is somewhat helpful.
Phoenix