Hi csalinas.m26,
ILD is only one of several specs that makes one material feel softer or firmer than another (see post #4 here) and the ILD of different materials or different types and blends of latex also aren’t directly comparable to each other anyway.
Different people can also have very different perceptions of firmness and softness compared to others as well and a mattress that is firm for one can feel like “medium” for someone else or even “soft” for someone else (or vice versa) depending on their body type, sleeping style, physiology, their frame of reference based on what they are used to, and their individual sensitivity and perceptions. This is all relative and very subjective and is as much an art as a science. There are also different types of firmness and softness that different people may be sensitive to that can affect how they “rate” a mattress as well (see post #15 here).
Unless you have a great deal of knowledge and experience in the industry with different types of mattress materials and components and their individual specs and know how different layering combinations and mattress designs feel to you when you combine different layers with different properties together in different ways and you can accurately translate all this complex information into your own “real life” experience that can be unique to you … I would tend to avoid using complex specs to try and predict how a mattress will feel or perform. When you try and choose a mattress based on complex combinations of specs that you may not fully understand or based on specs for single layers that are only part of the picture and that may not be as relevant or meaningful as you believe they are … then the most common outcome is “information overload” and “paralysis by analysis”.
I would always keep in mind that no matter how many specs you know about a mattress or how much you try and “analyze” specs to try and predict how a mattress will feel … the only way to really know how any mattress will feel to you as a whole will be based on your own personal testing or your actual sleeping experience.
Phoenix