Hi Shazb0t,
“Feel” is very subjective and depends on a combination of so many things including body type, sleeping positions, and individual differences in perception and the designs are so different that there is no way to know for sure how one would feel compared to the other for any particular person until you have tried it. I also don’t know the specifics of what you liked most about the Nature.
Having said that … if I had to make an educated guess … the combination you chose would “feel” firmer to most people both because the top few inches are firmer on average and the comfort layer is also thinner so you are closer to the firmer support layer.
Again … while there is no way to know how it will feel or perform for you in terms of PPP until you try it … if I had to guess I would agree that it would feel firmer to most people. In other words it would probably be more “supportive” but less pressure relieving.
There are different types or “species” of softness and firmness though that each person may be more sensitive to (see post #15 here) and there are also so many variables when you are trying to “match” or “translate” one design to another (see post #15 here) that it becomes a speculative exercise at best because there are too many unknowns and variables for anyone to know with any certainty.
It’s also quite possible that something very different than the Nature that you may initially consider to be a “mistake” ends up being better for you than the Nature in terms of PPP in your actual sleeping experience depending on the accuracy of your testing and how well it predicted your actual sleeping experience vs just the “showroom feel” of the mattress.
As an aside … if you had a 2" 22 ILD layer over a 6" 28 ILD layer it may be closer to the Nature (although again there would be no way to be certain and it may feel one way under one part of your body and different under another and the “feel” would also be different because the “range” of compression would be wider with a thicker mattress). With this combination both the top 3" and the top 4" would be close in terms of ILD and since the mattress was thinner overall the support layer would become firmer more quickly than the Nature as you compressed it more so it’s lower ILD may be offset by the thinner mattress. Of course none of this takes into account the difference in the cover because one is quilted with wool and the other is a thinner stretch cover which will both interact with the layers below them differently. 3" of 22 ILD over a 36 ILD core may also have some similarities although for many people would feel softer depending on how much they sink into the mattress.
The real problem with this type of speculation is that one person may say “wow … I can’t believe that you guessed so accurately” and then the next person will say “wow … I can’t believe that anyone could be so wrong” … and both of them would be correct because of the differences in their body types, sleeping positions, and individual perceptions along with how two very different mattresses interact with each person.
Phoenix