Hi Jewels,
The top quilting layer with 1.5 lb polyfoam is just a little thicker than I would normally like to see but it’s still less than 2" so it should be fine.
The 1" of latex and the 1" of 2.4 lb polyfoam are both high quality and durable materials.
The 3 lb visco lumbar support is a belly band not a full layer and it’s also under the other foam layers so this would be fine as well even though it’s only 3 lb density.
The insulator materials are also fine.
You can read more about the different types of innersprings in this article but even though continuous coils are a lower cost type of innerspring … the support layer isn’t the weak link of a mattress and continuous coils can provide good support for a mattress. I would make sure you are OK with any motion transfer that can be be part of innersprings that use coils that are linked with helical wire.
Overall I don’t see any significant weak links in the mattress and it would make a reasonable choice IMO … especially compared to most of the maintream mattresses that most people end up purchasing … although they aren’t in the same quality range as the PLB mattresses that you were also considering previously.
The specs of the Restonic two sided mattress that you mentioned and that I discussed in my reply here is still missing the quality/density of the top 2" quilting layer so I would want to know what it was before I considered it.
There is also more about the most important parts of the “value” of a mattress purchase in post #13 here that can help you make more meaningful comparisons between mattresses.
Phoenix