Hi equestride,
[quote]Well I napped for a little over an hr and while I didn’t have a lot of lower back pain my other body parts were hurting.
maybe we will take your suggestion and move the xfirm up and med on top and see how we do[/quote]
While a nap may not be enough to provide enough meaningful information … it certainly “points to” firmer layers being helpful for your back but changing the comfort layers instead of the support layers was probably the cause of the “other” symptoms you experienced because your comfort layers may now be too firm for you and may not be providing you with enough pressure relief (which is primarily the job of the upper layers of the mattress).
You can read a little more about primary support, secondary support, and pressure relief and the relationship between them in post #2 here and in post #4 here that may help you understand some of the “theory” behind different types of layering combinations.
Phoenix