Hi EPmattresshunter,
Unless you have a great deal of knowledge and experience with different types of mattress materials and specs and different layering combinations and how they combine together and can translate them into your own “real life” experience that can be unique to you … I would tend to avoid using individual specs such as layer thicknesses or ILD numbers or other complex specs to try and predict how a mattress will feel or perform for you and focus more on your own actual testing and/or personal experience. When you try and choose a mattress based on complex combinations of specs that you may not fully understand then the most common outcome is information overload and “paralysis by analysis”.
There is more about the different ways to choose a suitable mattress (either locally or online) that is the best “match” for you in terms of PPP in post #2 here that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for once you actually sleep on your mattress but when you can’t test a mattress in person then the most reliable source of guidance is always a more detailed phone conversation with a knowledgeable and experienced retailer or manufacturer that has your best interests at heart who can help “talk you through” the specifics of their mattresses and the options they have available that may be the best “match” for you based on the information you provide them, any local testing you have done or mattresses you have slept on and liked that they are familiar with, any special considerations you may have, and the “averages” of other customers that are similar to you. They will know more about “matching” their specific mattress designs or firmness options to different body types, sleeping positions, and preferences or even to other mattresses that they are familiar with than anyone else.
Assuming that two materials you are comparing are good quality and durable versions of that material and neither one would be a weak link in the mattress … the choice between different types of materials or components in a mattress is just a preference or a budget choice rather than a better/worse choice and one person’s preferences (including mine) may be very different from someone else. For example I personally prefer the “feel” of sleeping on latex vs memory foam but there are many people who don’t like latex at all and prefer the feel of memory foam vs latex. I also “like” the “feel” of comfort layers that use relatively thin layers of latex on top of relatively thin layers of memory foam because they provide some surface resilience from the latex with some of the slower “sinking in” feeling of memory foam underneath it. Other people prefer the “feel” of a slower responding and more motion isolating memory foam top layer with some latex underneath it so the “surface feel” is provided more by the memory foam which is modified by the resilience of the latex underneath it. There are almost infinite combinations of “feel” that are possible by combining different types of materials and components in different thicknesses and positions in a mattress but they are all just preferences … not better/worse choices.
The upper layers of a mattress are generally the weakest link of the mattress in terms of durability and are the layers where the quality/durability of the materials is particularly important. The regular deflection/compression of a foam material is what softens or breaks down foam over time and the softer upper layers of a mattress will deflect and compress more deeply and more often than the firmer deeper layers so the deeper support core of a mattress underneath the comfort layers is rarely the weakest link in the mattress so having a latex support core vs a high quality polyfoam support core would make little difference for most people in terms of durability.
You will also “feel” the properties of upper layers more than deeper layers as well so in most cases you would really be comparing the “feel” of memory foam with the “feel” of latex rather than the “:feel” of polyfoam with latex. There is more about the pros and cons of memory foam vs latex in post #2 here but the most reliable way to know which type of material you tend to prefer would be based on your own local testing on a range of mattresses that have either memory foam or latex comfort layers.
While it would depend on the specifics of the polyfoam or latex you are comparing … in very general terms latex is a more resilient (springy), point elastic (contouring), breathable, and more durable material than most types of polyfoam but you would feel much less of these differences if you are comparing deeper layers in a mattress than you would if you are comparing layers that are closer to the surface so there would be much less benefit to using a latex support core under relatively thick comfort layers vs using a good quality/density polyfoam support core.
If a mattress uses latex In middle transition layers rather than in the comfort layers (where you would feel the latex more) or the bottom support layers (where you would feel the latex less) then how much it would affect the “feel” of the mattress would depend on the type and thickness of the layers above it and on the body type, sleeping positions, and sensitivity of the person sleeping on the mattress. If the latex transition layer is in the same depth or position in the mattress as another mattress that uses polyfoam in the same depth and position and they both had the same type and thickness of layers on top of them then depending on the person and the thickness of the layers above them the latex could add some extra contouring and resilience to the mattress which some people may prefer and which some people would probably notice more than others.
Again though … I would keep in mind that I don’t have any personal experience with sleeping on any of their mattresses so they will know more about the specific differences in “feel” between their different models and would be the best source of guidance to help you choose between the different options they have available.
Phoenix