Hi winterk80,
Reading too much into reviews (either positive or negative) that don’t provide enough specific information is a common mistake that many consumers make when they are choosing a mattress (or a topper) and there is more about how reviews can be particularly misleading (again either positive or negative) in post #13 here.
Every manufacturer in the industry … regardless of the materials in the mattress … will have some percentage of “significant issues” which can be for many reasons. I’m not sure which specific mattress you are looking at or the specific issues you are referring to but assuming that they are about durability or sagging issues then you can read more about this in post #2 here.
Post #13 here has more about the most important parts of the “value” of a mattress purchase (which would apply to toppers as well) and outside of the suitability of a mattress or topper in terms of PPP … the most important part of the “value” of a mattress or topper purchase is the durability of the materials which will affect how long any material will maintain its comfort and/or support. There is more about the many variables that can affect durability and the useful life of a mattress (or a topper) relative to different types of materials and different people in post #4 here. As you can see … the most important part of the durability of a mattress or topper is the quality/durability of the materials inside them (regardless of the name of the manufacturer) which in the case of polyfoam or memory foam would be the density and in the case of latex would be the type and blend of the latex.
Phoenix