Hi PATP,
[quote]I think the Enlightenment as configured above is pretty close for me. It may be just on the edge of being too firm in feel for adequate pressure relief for me, but the postural alignment seems ok. I may like a little extra softness.
To soften the mattress as constructed, in the store I tried adding a 2" N2 soft natural talalay topper on top. This actually felt fantastic - soft and plush and great pressure point relief. But, for alignment purposes, I thought the cradle created was too deep.[/quote]
You are into some very subjective territory here about perceptions of softness because with the firmer top layer some people that are more sensitive to the firmness of the top layer would feel that the mattress felt firmer with the topper and with the additional thickness (thicker mattresses can feel softer) some people like yourself would feel that the mattress felt softer.
I would keep in mind that the depth of the cradle would be more of a preference choice (some people like the feel of sinking into a mattress more deeply) but alignment has more to do with how evenly you sink in rather than how deeply you sink in. Post #6 here can help you visualize what good alignment “looks like”.
With the thickness and softness of the comort layers the way you tested it you would already be in a softness range that could have some alignment risk so if you were to soften it further yet the risk would increase. This doesn’t mean that you would be out of alignment … only that I would be very cautious with a mattress that was as soft as you are considering. Deeper layers would have less effect on what you feel when you lie on the mattress (they can have a bigger effect on alignment and what you feel when you wake up in the morning) so I would be very cautious about using 3 layers of softer Talalay in addition to a softer Talalay topper. This would be a softer mattress than most people would do best with.
Every change you make will have some effect on both pressure relief and on support/alignment because all the layers in a mattress will have some effect on every other layer and the feel and performance of the mattress overall. In many cases the effects of making smaller changes in the bottom layer (such as changing from firm Dunlop to firm Talalay) would be too small for some people to feel at all but since you appear to be more sensitive then it’s very possible that you would feel it and it would provide a little more “spring” to the mattress. Changing any layer to a softer version would make the mattress softer but the effects of doing this with deeper layers will be more subtle than using softer layers that were closer to the sleeping surface. I think that changing the bottom layer to Talalay would probably be the “safest” of the changes you could make because some of the others would be more risky and I would sleep on the mattress first to see how suitable it is in “real life” before making any softer changes and then you can exchange a layer to make it softer if your experience indicates that you are still well inside the softness range that would be suitable for you.
The better options and possibilities I’m aware of in the San Francisco area are listed in post #2 here. There are too may unknowns and variables and subjective perceptions involved to be able to predict which mattresses would feel “equivalent” to you based on specs (either yours or a mattress) so you would need to rely on your own testing to decide this but since it’s clear that you do prefer very soft mattresses that are in a more “risky” range I would tend to focus on mattresses that have softer layers in the top 6" or so but I would be very cautious about using softer layers deeper than that.
Phoenix