Hi LEW,
I can certainly understand your frustrations and disappointment but I can also assure you that the latex you have tried isn’t “breaking down” or getting soft to the degree you are perceiving. Latex just doesn’t do this. After your first experience I thought it was possible that it was some kind of defective latex but with it also happening with your current mattress (which would work well for someone that was twice your weight for many years) it is clear to me that something else completely is happening that is somehow connected to your own physiology and perceptions.
I think part of this may be that the “feel” and response of latex is giving you the subjective perception that you are sinking in more than you really are which “translates” into subjective perceptions that are at odds with your expectations and what you are used to feeling on a mattress that is made of “stiffer” materials. If you were to put the layers on the floor and then test them for ILD according to any valid testing protocol you would find that the ILD hadn’t changed nearly as much as you believe it has … even though what you are feeling is very real to you.
Latex will soften much less than other foam materials and when one person’s experiences are so different than all the testing that has been done on latex and is also at odds with the countless people who sleep on latex over a period of many years or decades … then it’s reasonable to think that either the way that latex feels and responds is somehow not comfortable or suitable for you or that you (and your body) just need to get used to a material that responds differently from what you are comfortable with over a much longer period of time. You would not be the first person by any means where latex was not their favorite material or had difficulty adapting to how it feels and performs but it certainly isn’t because for some reason you alone are somehow softening the latex in your mattresses more than all the countless people who have slept on it for decades.
As you can see in my earlier reply to you in post #2 here (about latex softening) as well as post #4 here … subjective “feelings” about how much you are sinking in are certainly valid as a “feeling” but they come from your mind and thoughts and beliefs not from your body. They are a “feeling about” something based on thinking about it rather than the thing or symptom itself. Sometimes what we actually experience is “translated” through beliefs that we think are true … whether or not they actually are.
I know this isn’t likely what you want to hear but you aren’t the first person to “overthink” themselves into believing something that flies in the face of years of experience and seems to produce “evidence” that appears to confirm it. Your discomfort and pain of course are real and nobody wants to experience this for themselves or hear about it from someone else … but the reason you are attributing it to … the softening of the latex more than what would be considered “normal” … just isn’t what is happening and the actual cause behind your symptoms is somewhere else and a mystery waiting to be solved.
Phoenix