Hi JJR,
[quote]Now you know why I am confused … : )
My weight is around 158lb and I usually swap between back and side positions…however, on this bed i have been using mostly back for the last year since side position gets too uncomfortable too quickly…and I usually have to sleep on top of an additional comforter to prevent sinking into the bed a bit…[/quote]
This “points to” the mattress being too firm for you if you seem to gravitate to sleeping on your back from your side.
All the layers of a mattress will compress to different degrees when you sleep on it and it’s not really possible to know how much of the pressure relieving “cradle” comes from each layer in a mattress but it would certainly be true that the top 3" memory foam layer would be compressing more than the support layer underneath it. What you are describing about the surrounding area being firmer than the area you are sleeping on and how the foam displaces are all properties of memory foam to different degrees depending on the specific type and density and the temperature sensitivity of the memory foam. There is more about the pros and cons of memory foam in this article.
Based on some of your comments … it’s possible that you would prefer a latex comfort layer which is more resilient, can sleep a little cooler, has a more “on the mattress” feel, and is less motion restricting than slow response materials. There is more about how memory foam compares to more resilient materials such as latex in post #6 here but the best way to know which type of material you tend to prefer would be to try some latex and some memory foam mattresses locally because each person may have a very different opinion about the type of material they tend to prefer.
Given all of your feedback … and “on balance” … I would be tempted to try a softer latex topper in the range of about 2" or so which will give you a reference point to see how a softer more resilient topper will affect your sleeping experience although if you are sensitive to latex it may not be the best choice for you.
Polyfoam is also a more resilient material than memory foam (although not as resilient and point elastic and shape conforming as latex) and is also less costly than latex (it’s the material that you will fine in slightly firmer versions in most couches and upholstered chairs) and given your experience with your Dunlop topper this may also be an option that may be worth trying in a softer version. Did you decide to try again with your Dunlop topper on your mattress?
Either way … because you are in a trial and error mode I would make sure that you are comfortable with the return or exchange options that are available to you after a topper purchase so that you can experiment a little more with lower risk. Some of the big box stores have very good return options.
Post #2 here and the topper guidelines that it links to have some guidelines that you can use to choose a topper and also links to a list of some of the better online topper sources I’m aware of as well. Outside of local options in Toronto (post #1 here has a list of some of the better options I’m aware of in the Toronto area and some of these would sell toppers as well) … some of the better online sources that ship across Canada are also listed in post #21 here and some of them sell toppers that may also be worth considering.
Phoenix