Hi SleepDeprived,
OK … now I understand what you were asking and I completely agree with you that the “thickness” of a mattress sold as a benefit without regards to the specific materials inside … or which in many cases are just an excuse to add cheap low quality materials to a mattress for the benefit of consumer perception or the selling price of a mattress … are a waste of money and time. In most cases they can actually create bigger issues as the softer lower quality comfort layers on top will only soften and impress faster and the materials in the bottom of the mattress are so far away from the person on the mattress that they can become almost meaningless. The “ultra thick” mattresses that are so common and that usually include some type of pillowtop are often the type of mattresses that are sold to boost profit margins or to “trap” unwary consumers that really don’t know any better and can be much worse in every way (including durability and suitability) than a mattress that is more suitable to the specific needs and preferences of the person sleeping on it.
I completely agree with this as well and it’s always best to focus on PPP than on the comfort specs of a mattress. In most cases … once you set aside all the things that the mainstream industry “wants you to believe” and look for mattresses that actually work well in “real life” based on your actual experience you will almost certainly end up with a much more suitable choice in terms of quality and value. The “value” of a mattress that can be “tweaked” in various ways is also a bonus. Sometimes this involves layers that can be re-arranged or exchanged and sometimes this could be a local manufacturer that will open up the mattress and change out a layer at a very reasonable or in some cases no cost at all to make it more suitable for your needs and preferences. Some designs include a base mattress and a topper that can be exchanged or even replaced when necessary without having to replace the entire mattress.
This is almost certainly true although to some degree it will depend on the specific design of the mattress. If you start off with a mattress support core that is in the range of 6" to 8" then it’s not very likely that you would need 6" of padding above this. There is a little more about primary support, secondary support, and pressure relief in post #4 here and the role of deep support layers, transition layers, and comfort layers and how they work together. The simplest way though is to use the feedback from your body to tell you whether a mattress works well in terms of PPP and then make sure you know the quality of all the layers so you can identify any weak links or lower quality materials that would reduce the useable life of the mattress. In essence you are testing for the two main functions of a mattress which are comfort/pressure relief, and support/alignment along with the preferences you can “feel”. Beyond that all you really need is the information that tells you about the quality and durability of the materials in the mattress so that you know what you feel on the mattress will last longer before the loss of comfort and support leads to the need to replace the mattress. Much of what you pay for in a mattress is the quality of the materials (unless you are buying an ultra thick mattress where you are paying for more problems) because you can’t “feel” the quality and durability of the materials and lower quality and higher quality materials can feel the same in a showroom.
The industry would also have you believe that the warranty on a mattress is connected to the useable life of a mattress or the quality of the materials but this is just more “marketing” because a warranty only covers factory defects and the more rapid softening of lower quality materials isn’t considered a “defect” but just “normal” wear and tear. There is more about warranties in post #174 here. Even most retailers in the mainstream industry include the length of a warranty as a replacement for educating their customers about what is actually in the mattress and will use the length of a warranty as a selling tool to convince customers that longer warranties equals higher quality. Like the thickness of a mattress, it’s mostly meaningless except as a small piece of a bigger picture.
If you had a mattress that used a thinner memory foam comfort layer or layers in some combination with a more resilient polyfoam support layer or perhaps a transition layer of a couple of inches of softer polyfoam in the middle it would likely may be very similar to what you felt with 6" of memory foam on the floor with less risk involved.
Polyfoam and latex are both more resilient than memory foam although they can also be very pressure relieving (like memory foam). Latex is particularly pressure relieving in the right softness because of its ability to contour to the shape of the body (also like memory foam). The difference is that memory foam is always in a soft range (once it warms up to body temperature) and responds to temperature, humidity, pressure, and time (it gets softer as it stays compressed over the course of the night) so it can “allow” the heavier parts of your body to continue sinking in over the course of the night if the layers are too thick while polyfoam and latex only respond to pressure so it doesn’t change its firmness level and how it responds over the course of the night. Polyfoam, latex, and innersprings can also be made much firmer than memory foam so they can be used for support layers while memory foam isn’t suitable for use in the deep support layers of a mattress. Memory foam mattresses needs some kind of more resilient but firmer layer underneath it that isn’t affected by temperature and time underneath it as a support layer to “stop” the pelvis from sinking in too much and maintain good spinal alignment…
Phoenix