Hi Taylor,
The specs of the base layers and most of the other specs for the Optimum line are in post #48 here along with my thoughts about them.
2.2 lb polyfoam is actually pretty good density/quality (density is the primary factor in quality) and much better than the base layers that are used in the lower models in the line.
Regardless of the base foams though … the entire line has poor value when you consider that the memory foam is only medium density/quality (and the upper layers are usually the weak link of a mattress) and higher priced than many mattresses that use similar or better quality materials.
I would also bear in mind that there are many factors involved in the sleeping temperature of a mattress (see post #16 here) and if you are only looking for a “cooling layer” rather than looking at the combination of factors that contributes to sleeping temperature then you are likely buying more of a “marketing story” rather than real world performance.
Phoenix