Hi js715,
It can certainly make a difference yes but some people may notice it much more than others and some may not notice the difference at all. It will also depend on the person and what is above and below the latex.
Once again … how much of a difference someone will feel with different ILD’s depends on all the other layers that are above and below it and on the individual person and their body type, sleeping style, and individual sensitivities. While most people wouldn’t notice much difference between smaller differences in ILD (in the range of 4 or less or sometimes more) if the rest of the mattress was exactly the same, some people are much more sensitive than others to smaller differences in a mattress. Your own personal testing and experience on both is the most reliable way to know. If you are dealing with a knowledgeable and experienced manufacturer (such as Sleep Craft in Lewisville if that’s who you are dealing with) then I would also put a lot of weight on their suggestions and guidance about the differences between what you are testing and another design you are considering that you haven’t tested in person (which would be a little more risky than a mattress you’ve tested that is the same as you end up buying). Your careful and accurate testing will tell you much more than ILD and other mattress specs or any “theory at a distance” about which mattress is the best match for you in terms of PPP. Nobody else can feel what you feel on a mattress. You need the quality specs of a mattress to make sure there are no weak links in the mattress and to make more meaningful comparisons but your testing for PPP is much more important than any “comfort specs” or “theory”.
In better innerspring mattresses this is common yes … in lower quality mattresses then not as much (and the layers would shift more and the mattress would have a higher risk of losing its shape).
Pillow preferences are even more individual than mattresses so I don’t think it’s possible for anyone to recommend a specific pillow that someone else may like but the pillow thread here may be helpful and has some good basic information about choosing a pillow and some feedback from the members here.
Phoenix