Hi MM2014,
The break in and adjustment period for a new mattress can vary with the person, on how different your new mattress is from your old one that your body is used to, and with the specifics of the mattress, so for some people it can be a matter of a few days (some people don’t seem to notice it at all) and for others it can take as long as a few months but for most people it would be a month or less. From the sounds of your experience and considering that latex is a very durable material that doesn’t soften as much as other materials I don’t think that another week will make a significant difference and it sounds like your mattress is probably too firm for you.
While anything is possible because firmness and softness is so subjective and is relative to the different perceptions of each person … if a floor sample was actually 36/36/36 then it’s very unlikely that anyone would feel it was softer than a mattress that was 28/36/28 in side by side testing in “real time” and it’s much more likely that the testing you did in the showroom wasn’t long enough or accurate enough to approximate your “real life” sleeping experience. Because our memory of firmness and softness is not particularly accurate and is also fairly subjective and relative … if there is some time between when you test a mattress and then test or sleep on it later then the time and your experiences in between can alter your perceptions of how soft or firm it is as well. It’s not uncommon for example to test mattresses early in the day and then go back and test the same mattresses later in the day or the next day after you have tested other mattresses and discover that the mattresses that you tested feel different than you remember they did because your frame of reference has changed with time and as you tested other mattresses.
The cover and the quilting of a mattress can have a significant effect on how a mattress feels compared to sleeping directly on latex layers and an additional softer layer on the bottom can also affect how a mattress feels as well. Some people are also more sensitive to differences between mattresses than others and there are also different types of firmness and softness that different people are more or less sensitive to as well (see post #15 here) so each person’s experience or comparisons can be very different from someone else. Some people will feel that certain changes make a “significant” difference and others may not feel the same changes at all.
Softness and firmness is always relative to the individual person so a mattress that feels firm to one person can feel soft for someone else depending on their body type, sleeping positions, and sensitivity so a 32 ILD support core with a 2" 24 ILD comfort layer may feel firm for some people (particularly if they are lighter) and can feel soft for others depending on their reference points for firm and soft and all the other variables that affect the sensation of firmness and softness for each person. In the final analysis your own experience is the only way to know which mattress feels firm or soft to you and “how” it feels firm or soft. The same would be true with the transition between the firmness of the layers. With a 2" comfort layer you would feel “more” of the relative firmness of the layer below it than you would with a thicker comfort layer (particularly with side sleeping) but this will also depend on the specifics of the cover and any quilting layers as well and the body type and sensitivity of the person. For some people it would work well and they would prefer the “feel” that comes from a bigger differential between the firmness of the layers and others may find that a softer support core would be preferable. These are all variations that can only be known based on your own personal experience.
I would keep in mind that there are different types of support and that firmer doesn’t necessarily mean more supportive or produce better alignment. There is more about primary and secondary support and their relationship to pressure relief in post #4 here and in post #2 here. I would also keep in mind that latex is a more “on the mattress” material than memory foam (which has a more “in the mattress” feel) although the softest versions of latex (in the teens) have a “somewhat” more “in the mattress” feel than firmer versions.
Because only you can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved for anyone else to know with any certainty what you will feel on any specific combination of materials based on specs (either yours or a mattress) or “theory at a distance” (see mattress firmness/comfort levels in post #2 here) … the only thing that is clear from your comments and feedback is that you will likely need a softer comfort layer and possibly a softer core as well. If you have the option to try one first and still make further changes again I would probably start with a softer comfort layer and then if this is still too firm for you then switch to a softer core as well although this would depend to some degree on your weight and sleeping positions because higher weights will tend to do better with firmer materials and different sleeping positions also tend to do better with different combinations (side sleepers for example tend to need or prefer thicker/softer comfort layers). I would also keep in mind that a mattress that is too firm is easier to “fix” with a topper that can add additional softness and pressure relief than a mattress that is too soft which would normally require the removal and replacement of the layers that were too soft.
Phoenix