Hi PrincessAndThePocketCoil,
Serene foam is one of the "newer’ generation of high-performance polyfoams, which are of a higher density and good at pressure point relief, but do not have any of the viscous properties (it is not a memory foam). It is also not a latex foam. Carpenter introduced Serene in 2015 and re-launched it in 2016. It is generally a higher density (2.5 lbs as an example) and it is CertiPUR-US certified. This generally would be a good quality and durable plush material. It is not technically a high-resilience foam, as that would require a 2.5 density or above, along with a compression modulus of 2.4 or above.
High performance polyfoams such as this are becoming a bit more popular, some to offer the conformation and point elasticity found in memory foam, but to be more open-cell and breathable, faster in recovery, and not so temperature dependent. Others are designed to be closer to latex in their characteristics. And then some are simply designed to be more durable versions of low-density polyfoams.
These foams are usually located in the uppermost layers of a mattress to take advantage of their point elasticity, and are sometimes offered as a topper. The overall feel of any mattress is of course dependent upon all of the layers within a mattress, and the “deeper down” these foams are placed within a mattress (even beneath a thicker covering), the less noticeable their softness will be.
High performance polyfoam or memory foam certainly can provide some “tempering” of the buoyancy of latex. If you like the resiliency and responsiveness of latex, but just don’t want it to feel “too bouncy”, you can locate the memory or polyfoam beneath the latex upper layer. If you like the durability that latex provides and the good conforming support, but think that it’s too “lively”, you can place the latex beneath an upper layer of memory or polyfoam. The nice thing with a component DIY system is that you can rearrange layers and experiment at home.
Phoenix