Hi Cassie88,
There are 4 main “categories” of latex that you will encounter. This is because there are two main “types” of latex that use different production methods (the Talalay method and the Dunlop method) and each of these can be made with either natural latex (NR from the rubber tree) or a blend of natural latex and synthetic latex (usually SBR made from chemicals that are “similar” to NR). While there are variations in each method, the Talalay method is the most expensive method of manufacturing and NR is the most expensive material.
This means that you will generally encounter 100% natural Talalay, 100% natural Dunlop, blended Talalay, and blended Dunlop. There can be variations in each of these categories depending on the complex compounding formulas used by each manufacturer and different ratios of NR to SBR used in different blends. The exact formulas used by each manufacturer are a closely guarded secret.
In general though … 100% natural Talalay is the most expensive, 100% natural Dunlop and blended talalay are a little lower and are roughly the same cost, and blended Dunlop is the lowest cost of all. There is also a version of dunlop which uses “organic” rubber rather than just “natural” rubber which means it uses natural rubber that has been certifed organic. Because organic certification adds to the cost of a material (even if it is the same as “natural”) this would be in the same range as 100% natural Talalay. There is no “organic” Talalay.
There is more about the different types of latex in this article and for the more technically inclined … more about the differences between NR and SBR in post #2 here and more yet in post #2 here.
Overall … 100% natural Dunlop and blended Talalay are generally considered to be the most durable versions of latex (for different reasons as the article, posts, and links explain).
In terms of “value” … your first option uses blended talalay but uses thicker layers while the second uses natural Dunlop and then what appears to be natural Talalay (although there is some confusion in terminology and blended talalay is often called “natural” instead of 100% natural talalay). The first would seem to have better “value” based on the latex content along but there are many other factors in a mattress (such as the ticking/quilting used which can be a significant part of the cost) which can affect the price of the mattress.
This brings us though to the most important part of your choice which is the suitability of the mattress to your needs (pressure relief and alignment) and preferences.
Your first option has a VERY soft layering if the ILD’s are correct (which I would question). 24 ILD is normally used as a comfort layer and would very rarely be used as the main support layer in a mattress. This would be very “risky” in terms of alignment … although your own testing would be more accurate than “theory” and you could be the exception. I would test this very carefully for alignment in all your sleeping positions. This would be a very soft mattress with lower levels of support than would be the norm, particularly for your weight.
The second option would be much firmer in it’s “basic layering” because the Dunlop is usually firmer than the same ILD of Talalay (once you get past the first 25% compression). With the extra 3" topper this would likely be clloser to the first in terms of pressure relief but the support layers would likely be more appropriate or at least more “normal”.
Both blended latex and 100% natural latex are considered to be very “safe” materials and both are usually certified by reputable certification agencies in terms of offgassing and safety.
My decision would likely depend on which I believed would provide the best combination of PPP (Pressure relief, Posture and alignment, and Preferences). They would seem to have similar “value” (assuming that the comparative cost included the 3" topper in your second choice and assuming that the other components are also similar).
No matter what the value or quality of a mattress … if it is not suitable in terms of PPP … then its value would not be nearly as important.
Phoenix