Hi rkk5000,
As you can see in post #13 here … I don’t pay much attention to mattress reviews … or topper reviews (either good or bad) because one person’s “too firm” can be another person’s “too soft” and specifics of the mattress under a topper will also have a significant effect on how it feels.
There are too many variables and unknowns for me to know how well a topper will work for you on your mattress (outside of the generic topper guidelines that are based on your own experience) because I can’t feel what you feel and I don’t have any personal experience on this topper in combination with a mattress that is similar to yours and different memory foams can have very different properties even if they are the same density (see post #9 here and post #8 here).
In terms of quality/density though a 4 lb memory foam is inside the guidelines for the quality/density range that I would consider.
As I mentioned previously … knowing the details of their return or exchange policies would likely become one of the most important parts of a topper purchase if you need to do some trial and error and aren’t certain that a specific topper will work well for you in combination with your mattress.
It’s possible yes but again it’s not possible to “diagnose” the reason for someone’s specific pain or discomfort on a specific mattress with any certainty because there are too many unknowns and variables involved (particularly if there are pre-existing conditions that aren’t connected to a mattress) and it would be much like a doctor trying to diagnose back issues on a forum without being able to see or examine a patient. Having said that … post #2 here and the posts it links to has much more information about the most common symptoms on a mattress and some of the reasons that can cause them (to the degree that they are related to the mattress) that can help with the “detective work” that may be necessary to identify the specific source or sources of any symptoms you are experiencing.
With a mattress that is too firm (and your mattress is on the firmer end of the scale which is part of the reason that I’m suspecting it may be too firm) it’s quite possible that you are “twisting” away from pressure points and some of your back issues are related to rotational alignment issues (twisting of the back and spine) and not just from horizontal alignment issues.
It can take some trial and error to “fix” a complex set of symptoms and there could be multiple causes for many symptoms as well so it may not all be from a single cause (pillow issues for example can play a role in upper body symptoms) but the most effective way to identify the types of changes that are most likely to succeed is to use your own experiences as a reference point and “pointer” by contrasting and comparing how your symptoms and experiences change on a mattress/topper combination compared to the mattress by itself. The changes between two sleeping systems (which symptoms improve and which get worse) can act as a reference point and can help “point the way” to any further changes (thicker or thinner toppers or firmer or softer toppers) that may be necessary or that have a higher chance of success when you can’t test a specific combination in person before you purchase a topper.
Phoenix