Hi tull2001,
You’re certainly heading in a great direction.
I would be very cautious about using other people’s experience on a mattress as a guideline for choosing the softness/firmness level that may be best for you. The most reliable source of guidance to help you choose a firmness level would be the manufacturer themselves who will have much more knowledge and experience with helping their many different customers choose a firmness level that has the best chance of success than anyone on the forum (who would only be familiar with what works for them). A mattress that is “way too firm” for one person may be “way too soft” for the next. The more information you can provide them in a more detailed conversation on the phone (or on their chat), the more you can help them to help you choose the firmness level that you believe will work best for you (see mattress firmness/comfort levels in post #2 here).
If you are still uncertain after a more detailed conversation with Dreamfoam … then it may also be worth considering one of their customizable mattresses where you have the option of exchanging one firmness level for a different one after your purchase just in case your sleeping experience indicates that your original choice was either too firm or too soft for your specific needs or preferences.
For reference … there is more information about the OMF Serenity Latex in post #6 and #7 here. While they do list the ILD of the two latex layers on each side of the mattress … they don’t mention the thickness of each layer (NOTE ADDED: The top 19 ILD layer is apparently 1" and the second 24 ILD layer is apparently 2") but this isn’t important because your testing will tell you whether the combination is a good match for you in terms of PPP.
Phoenix