Hi Jewels,
Unfortunately none of this includes the foam quality/density information that I would need to make any meaningful comments about the mattress or whether it has any weak links in the design (see this article).
There is also more about edge support for innersprings in post #2 here. If the polyfoam that they use is CertiPur certified or is made in North America then most people would consider it to be “safe” although there may be some people that are more sensitive or with certain health conditions (such as Multiple Chemical Sensitivities) that would prefer to avoid polyfoam (or memory foam) completely.
Sometimes who you deal with and their knowledge, experience, service, and transparency can be one of the most important parts of a successful mattress purchase and some of the options in post #2 here may be well worth considering. Finding a retailer/manufacturer that already knows what you would otherwise need to learn can save you the time and frustration of dealing with retailers that either can’t or won’t find out and provide you with the information you need to know to make an informed choice.
Phoenix