Hi swarm,
You can see some comments about the Ambiance in this topic. While it may be a good match for you in terms of PPP … there are certainly thicker layers of “unknown” and probably lower quality/density polyfoam than I would be comfortable with and it would be a risky choice in terms of durability.
Being a pillowtop this one probably has even thicker layers of “unknown” and lower quality polyfoam than the Ambiance (you can see a very general description here) and the only known “high quality” layer in this mattress is the latex which is right on top of the springs and all the other “questionable” layers are above it and closer to the top of the mattress where quality and durability is even more important (a mattress will tend to soften and break down from the top down) so depending on the thickness and density of the “unknown” layers it could be even riskier than the Ambiance in terms of durability.
The strategy I would generally use if you aren’t able to find out the type and thickness of all the layers in a mattress that is a good match by itself but where you can’t confirm the quality and durability of the materials would generally be to try and minimize the thickness of any unknown layers in the mattress (which usually means choosing a mattress that is firmer than you would be comfortable with) and then adding a good quality topper to provide the comfort and pressure relief that you may need (the topper would be instead of upper layers of lower quality materials that are “built in” to the mattress).
Phoenix