Hi HoosierLife,
The specs you received for the Beautiful aren’t quite correct and you can see the correct specs for all the PLB mattresses in post #2 here.
There is no “standard” definition or consensus of opinion for firmness ratings and different manufacturers can rate their mattresses very differently than others so a mattress that one manufacturer rates as being a specific firmness could be rated very differently by another manufacturer. Different people can also have very different perceptions of firmness and softness compared to others as well and a mattress that is firm for one can feel like “medium” for someone else or even “soft” for someone else depending on their body type, sleeping style, physiology, their frame of reference based on what they are used to, and their individual sensitivity and perceptions. This is all relative and is as much an art as a science. There are also different types of firmness and softness that different people may be sensitive to that can affect how they “rate” a mattress as well (see post #15 here). In other words you will always need to test a mattress for you to assess how firm or soft it feels to you (hopefully using the testing guidelines in the tutorial post) regardless of whether it feels firm or soft to someone else or how anyone else may “rate” it.
There are also different specs besides just ILD that can affect how soft or firm a mattress feels (see post #4 here) but it would probably be fair to say that in very general terms 21 - 24 ILD would be in the upper end of most people’s “soft” range.
There is 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” although with careful testing on a mattress this may be more than you really need to know.
I would be somewhat cautious with the Beautiful or any mattress that uses 6" of softer latex in the top layers when you are in your weight range and I would make sure that you have tested it carefully for alignment using the testing guidelines in the tutorial because there would be a greater risk that you would be sleeping out of alignment which can lead to lower back pain in the morning.
That you prefer the pressure relief of the softer Beautiful over the firmer Nature but I would make sure that what you prefer and what you need are the same thing.
There is more about the differences between Talalay and Dunlop in post #7 here.
Phoenix