Hi domtiger,
As you mentioned firmness and softness is very subjective and relative to the body type, sleeping positions, and sensitivities and preferences of each person. There are also different types of softness and firmness that different people are more or less sensitive to (see post #15 here). While different people describe the sensation or feel of sleeping on latex in many different ways … it’s probably fair to say that “on average” there are more people who aren’t familiar with the feel and performance of latex that would describe it as being firmer than they expected than softer than they expected.
The down side of buying any mattress that is too firm (latex or otherwise) would be that it’s not a good match for you in terms of PPP in which case you won’t sleep well on it either because of pressure issues or because of alignment issues and how well you sleep on a mattress is the most important part of the “value” of a mattress purchase (see post #13 here). Of course it’s easier to “fix” a mattress that is too firm by adding a softer topper than it is to “fix” a mattress that is too soft (which generally requires removing and replacing the layers that are too soft rather than adding to them) but choosing a topper that is a good match for you in terms of PPP on a specific mattress can be somewhat challenging when you can’t test a mattress/topper combination in person and can add another level of uncertainty and risk to your choices (see post #2 here). Of course with a component mattress that allows for a layer exchange you can generally make a mattress either firmer or softer in various ways but the goal is always to make the choice that has the best chance of success and I would avoid purposely choosing a mattress that is either firmer or softer than your ideal.
There is more about the different ways to choose a mattress (either locally or online) that can help you identify and minimize the risks involved with each of them in post #2 here.
The type of materials and components in a mattress are primarily a preference choice and not as much a “better/worse” choice. The comfort layers of a mattress are generally the weakest link of a mattress in terms of durability not the support core so these are the layers where higher quality and more durable materials are the most important although there are some cases where the durability of the deeper layers can become a more important factor such as with heavier body types or thinner comfort layers where the support core will be compressed more deeply and be more subject to the compression forces that soften or break down a material or component when you sleep on the mattress. There is more about the many variables that can affect the durability and useful life of a mattress relative to different people in post #4 here.
Phoenix