Hi rsvoir,
I’m normally don’t provide specific suggestions on the forum because it usually would require a phone call to get some of the more nuanced information that good suggestions normally require (which of course isn’t possible) and even with more limited information provided on the forum I just don’t have the time available to put in the analysis time it would require into making individual suggestions … but your circumstances give me a chance to share some of the thinking behind layer choices so I decided to make an exception this time :).
A recap of some of your your height/weight and sleeping position information from earlier posts include …
[quote]My wife is ~125 lbs, 5’4" and wants an extra firm. I am ~225 lbs, 6’2" and want a firm. I expect the new mattress to provide good support and durability (i.e., have minimal sagging) for at least 10 years, and to sleep cool since we both sleep hot.
We both start off on our stomachs but during normal night movement, I think we each have ended up sleeping a little more on our shoulders than we realized. At least for me this has created a little pressure in the shoulder area, so I will definitely be softening up the top a little via the 3rd layer of latex.
Initial results though are that it is slightly too firm on my shoulders when i sleep on an angle (ie, halfway between stomach and side with one shoulder into the mattress). For my wife, this same position is giving her quite a bit of pressure (she weighs ~100 lbs less than me so feels the mattress is pushing her off it rather than allowing her to sink into it).[/quote]
From this It appears that both of you sleep on your stomach and possibly in a “side forward” position and possibly on your side as well. I don’t know how much time with each and I didn’t see anything about your body shape (flat, curvy, athletic etc) which would also make a difference
Perceptions of firmness are also very subjective. For example … your wife is sleeping on an extra firm layer already (see the rating for 36 ILD here) but doesn’t like it so she needs something softer than she thought (not surprisingly because of her weight).
If you are both primarily a stomach sleeper then “thinner is better” so I would tend towards 2" unless you spend a significant amount of time on your side in which case you may need the extra inch. The difference between 22 and 24 is insignificant.
Since she’s lighter I would normally go in the lower end of the typical 19 - 24 ILD soft range (around 19 ILD) but she also prefers firmer mattresses it seems and if her body type and sleeping positions could “get away” with only 2" I would lean towards 2" of about 24 (or in that range). This would allow some of the firmness of the deeper layers to “come through” but also provide some cushioning. If she wanted firmer yet (using her “best judgement”) then I would be looking in the range of 28 (32 is getting too close to the 36 that she’s not comfortable with).
For you is seems that you need a little less extra softness than her so I would also be tempted to go in the 2" range both because of this and because you also spend time on your stomach and I would be looking in the ILD range of 24 - 28 because of your higher weight.
If you decided to go thicker then I would increase the ILD to compensate for the extra thickness.
Because it’s easier to add to what you have than remove it though … adding only 2" would allow you to keep the option of adding another inch (either over or under the top layer) if you need it because you couldn’t remove an inch if you went with a 3" topper. This is a more incremental approach.
You could also order one side at a time so that each of you could try it and then use your experience to decide on the other half of the layer (assuming you are comfortable with a split top layer because this would typically need a quilted cover to go with it to even out the split unless you glue the layers together).
If you plan to have a single top layer that isn’t split because you want a stretch knit cover then 2" of 28 ILD may be a good compromise between you that was more in a medium range (which would feel firmer for her). This is also based on the idea that if there are two seemingly similar choices that I would lean towards slightly firmer. This would still allow you to add another inch underneath it that was split if you needed it.
Of course this is all “best guess” with somewhat limited information and YMMV.
Phoenix