Hi hose406,
All of them?
As you can see in post #2 here and post #2 here I personally wouldn’t deal with FBM. They also don’t sell Talalay latex (or latex that is 20 ILD) although they say they do. I would personally deal with suppliers where you can have more confidence that what they claim they are selling is what they really are selling and what you would be receiving.
As you can see in post #3 here and as I mentioned in my previous reply … there is no way for me (or anyone) to know with any certainty what you will feel on any particular design unless you lie on a similar mattress (or sleep on it) and let me know how it works for you in terms of PPP (Pressure relief, Posture and alignment, and Personal preferences).
If you have some reference points of mattresses and designs you have slept on where you know the specifics of all the layers and can provide feedback about how they worked for you I may be able to offer some insights that would be helpful in terms of any changes that you want to make but without your feedback about mattresses you have tested where you know the details of all the layers … then it’s not possible for me to know how anyone will feel on any particular design based on “theory at a distance”.
I also wouldn’t trust the specs of what they are selling you because even something like the compression modulus of the foam can make a bigger difference than ILD and they don’t seem to provide accurate specs about what they are selling.
I would personally deal with a reliable supplier or manufacturer where you know what they are selling is what you will receive, where they have already done the designing, and where you will have access to better information and ideas about what may work for you and can make exchanges at a reasonable cost if you guess wrong about your layers.
Phoenix