Hi Britchap,
Yes … microcoils are a type of pocket coil that is designed to provide pressure relief in the comfort layers. They are a very durable component and have the advantage that they are generally a lower cost than specialty foams such as latex and memory foam. There are many high quality mattresses that use them in combination with other materials and choosing a mattress that uses them would be a preference choice based on how they feel and PPP. It certainly wouldn’t be a weak link in the mattress or a durability issue.
Of course using a microcoil in a coil on coil mattress would increase the coil count of a mattress (because the number of coils in the microcoil would be added to the number of coils in any innerspring) but coil counts are more about marketing and mostly irrelevant anyway … especially when you are using a coil count that includes two separate components.
There is no such thing as a layer that is “too thick” or “too thin” because if a mattress is a good match for you in terms of PPP then the type and thickness of the materials are “right” for you. These are all choices that would be based on your personal testing and preferences.
I’m not sure where you read that 2" of foam would be excessive in terms of suitability but if the mattress is a good match for you in terms of PPP then the individual layers and components are the “right” thickness for you. Side sleepers do tend to need thicker and softer comfort layers to relieve pressure points than other sleeping positions but your testing will confirm whether any mattress is suitable for you regardless of the specifics of the design.
In terms of durability (which is a completely different issue from the suitability of a mattress) … I would tend to be cautious if a mattress uses 2" or more of lower quality/density materials in the comfort layers (see the guidelines here) but polyfoam comes in a wide range of grades and quality levels and Texas Mattress Makers uses higher quality materials and foams in their mattresses than the major manufacturers. They will also provide you with specific information about the type and quality of all the foam in their mattresses.
If you have tested the mattress for PPP and it’s a good “match” for you and you know the type and quality of all the materials and components in your mattress and there are no weak links in the mattress then you would certainly have no cause for concern.
Phoenix