Hi desidude,
[quote]Top layer - 1" talalay latex - ILD 28 (I liked this firmness)
layer below - 2.5 foam HB foam - 6"
layer below - 1535 foam 3"
I hope this makes sense. If so, how can I customize this mattress with similar firmness, with better comfort and quality?[/quote]
Unfortunately there are too many unknowns, variables, and personal preferences involved for anyone (including me) to make “comfort suggestions” based on specs (either yours or a mattress) or “theory at a distance” (see mattress firmness/comfort levels in post #2 here) because comfort doesn’t have a specific meaning and is just too subjective and relative to each person. Your own personal testing or sleeping experience is really the only way to know how well a mattress will match your specific needs and preferences in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences).
There is more about all the variables that can affect durability in post #2 here and the posts it links to but in very general terms the upper 5" or 6" of a mattress will generally be the weakest link in a mattress and using higher quality more durable materials in the upper layers will generally have the biggest effect on durability. In this case the top two layers (the 1" of Talalay latex and the 6" of 2.5 lb polyfoam) are both very durable materials and there would be no weak links in the mattress the way it is. The 3" 1.5 lb polyfoam 3" layer on the bottom would be too deep in the mattress to have a significant effect on durability with 7" of foam above it.
Outside of completely changing the mattress into a different type of mattress completely … there aren’t any changes that I would make to it if it’s a good match for you in terms of PPP.
Phoenix