Hi MaryPT,
I certainly understand this … but I tend to focus on the suitability of a design rather than the specific material because any material in the right design can provide what I call good PPP (Posture and alignment, Pressure relief, and Personal preferences) which is the “bottom line” and the most important function of a mattress. While different materials certainly have different properties and some will prefer one over another … IMO any material in an “appropriate” amount can be part of a suitable mattress design that can provide for the needs and preferences of different people.
Most of the “suitability” of a mattress comes from its design and how the materials are used and interact together … not just the types of materials themselves. For example for some people a suitable support layer with a 3" comfort layer may work well but for others this same support layer may work much better for their body type or sleeping style with only a 1" or 2" comfort layer … either of which would produce a very different mattress.
There is some general information about different materials and mattress designs and how they may interact with different types of people and sleeping styles in the mattresses section of the site (you can just hover over the link to see the individual articles).
There is also more about primary or “deep” support and secondary or “surface” support and their relationship to firmness and pressure relief and the “roles” of different layers in a mattress in post #2 here and in post #4 here that may also be helpful in clarifying the difference between “support” and “pressure relief” and “feel” that may be useful as well.
Since you are a health professional interested in sleeping posture especially … this book has some of the best information I’ve ever read about the characteristics of an “ideal” sleeping surface" for different types of people and I would highly recommend it.
A few forum posts which may also be of interest to you include …
https://forum.mattressunderground.com/t/futons-looking-at-otis This is a primary reference post that I often refer people to.
https://forum.mattressunderground.com/t/sealy-embody-introspection (particularly worth reading as well)
https://forum.mattressunderground.com/t/effects-of-layers-and-thickness
https://forum.mattressunderground.com/t/what-is-the-best-quality-mattress-available
https://forum.mattressunderground.com/t/aloe-alexis-and-back-pain
https://forum.mattressunderground.com/t/ultimate-dreams
https://forum.mattressunderground.com/t/latex-mattress-choices
https://forum.mattressunderground.com/t/can-anyone-tell-me-about-these-two-mattresses
https://forum.mattressunderground.com/t/wondering-why-my-lower-back-is-achcy-in-the-morning-only
https://forum.mattressunderground.com/t/all-latex-in-nyc
https://forum.mattressunderground.com/t/new-latex-mattress-too-firm
https://forum.mattressunderground.com/t/fine-tuning-guidance-with-sleepez10000
https://forum.mattressunderground.com/t/aloe-alexis-and-back-pain
https://forum.mattressunderground.com/t/fine-tuning-our-sleepez-10000
https://forum.mattressunderground.com/t/brooklyn-bedding-best-mattress-ever
I know that this is a long list and some of the information in these is somewhat redundant but I did a quick scan for some information that I hoped may be of some interest to you for some “leisure time reading” 
Thanks again for taking the time to share your insights
Phoenix