While I can certainly help with “how” to choose … It’s not possible to make specific suggestions or recommendations for combinations of materials or components because the first “rule” of mattress shopping is to always remember that you are the only one that can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved that are unique to each person to use a formula or for anyone to be able to predict or make a specific suggestion or recommendation about which mattress or combination of materials and components or which type of mattress would be the best “match” for you in terms of “comfort”, firmness, or PPP (Posture and alignment, Pressure relief, and your own Personal preferences) or how a mattress will “feel” to you or compare to another mattress based on specs (either yours or a mattress), sleeping positions, health conditions, or “theory at a distance” that can possibly be more reliable than your own careful testing (hopefully using the testing guidelines in step 4 of the tutorial) or your own personal sleeping experience (see post #2 here).
I know you said you’ve already done some reading on the site, but just in case you haven’t read it yet … the first place to start your research is the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choice.
Two of the most important links in the tutorial that I would especially make sure you’ve read are post #2 here which has more about the different ways to choose a suitable mattress (either locally or online) that is the best “match” for you in terms of “comfort” and PPP (Posture and alignment, Pressure relief, and your own Personal preferences) that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for and post #13 here which has more about the most important parts of the “value” of a mattress purchase which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability (how well you will sleep), durability (how long you will sleep well), and the overall value of a mattress compared to your other finalists based on all the parts of your personal value equation that are most important to you.
Assuming that the materials in a mattress you are considering are durable enough for your body type (latex is extremely durable) and meet the quality/durability guidelines here relative to your weight range (which I think you are referring to that you have already read) … the choice between different types and combinations of materials and components or different types of mattresses are more of a preference and a budget choice than a “better/worse” choice (see this article).
The most reliable source of guidance would be a more detailed phone conversation with Brooklyn Bedding, as they would have your best interests at heart and can help “talk you through” the specifics of their mattresses and the properties and “feel” of the latex they are using and the options they have available that may be the best “match” for you based on the information you provide them.
A good quality latex mattress core will certainly be a very supportive material. You probably don’t have access to a laboratory with white-light raster line triangulation (WLRT), so we have to defer to your initial impression when testing a product in a showroom. Sometimes it’s not so much that you are able to tell if a product is “good enough” in what it does, but instead that it isn’t “doing the job.” With the mattresses you tested, you would want to note that when you were on your side that you did not sag “excessively” in the abdominal/thoracic area. When trying out the product on your back, you’d want to make sure that you weren’t sinking in too excessively, what is commonly referred to as the “hammock effect.” Of course, these evaluations are subjective, but your opinion is the one that matters the most. You’re starting with quality materials, and this gives you the best chance at success. Quite often you’ll read that your spine should be absolutely straight, but this is not the case. We all have individual variations in our kyphotic/lordotic/scoliotic curvatures, so subjectively evaluating the product in the showroom will be the best way to evaluate your own personal PPP.
For more details, there is more about some of the differences between a latex support core and an innerspring support core in post #28 here and the posts it links to but the choice between them would really be a preference and/or a budget choice rather than a “better/worse” choice because innerspring and latex support cores are both very durable components.
Latex is one of the most durable materials we can use in a mattress and it looks as if you’re considering a few choices that use high quality materials.
If you’re looking for more detailed information on how latex compares to other materials, there are clear differences between the durability of different materials and mattresses and there are many factors involved that will affect how long one mattress will last relative to another one. There is more about the different factors that can affect durability and the useful life of a mattress in post #2 here.
Some relative comparisons of different materials and components are also in post #3 here.
There is also more about how the suitability of a mattress choice and the sensitivity of each person to a range of comfort/pressure relief and support/alignment can affect the useful life of a mattress for each person in post #2 here.
What this means is that a mattress will generally have to be replaced long before the materials themselves have completely worn out or broken down (like in your 24 year old mattress) because foam softening and the breakdown or permanent compression of the materials or components in a mattress will have different effects on different people and any specific estimates for any particular person may be a “rough guess” at best. What can be said with certainty is that higher quality materials that soften or change more slowly will maintain their comfort and support and last longer than lower quality materials that soften or change more rapidly, latex is the most durable of the different types of foam materials, higher density memory foams and polyfoams will last longer and maintain their properties longer than lower density foams of the same type, and that the layers both above and below any specific material or component in a mattress will affect the durability of that material as well.
While the latex in a core layer is a more durable material even than good quality polyfoam or an innerspring, since the core layer is less subject to mechanical compression than the upper layers and are generally firmer (firmness is a durability factor) they will last longer than the same materials used in the comfort layers. To the degree that you are compressing the support layers “through” the comfort layers … the latex will be more durable than polyfoam but neither is likely to be the weak link of a mattress in most cases.
Besides a potential increase in durability to differing degrees (depending on the person and the layers over it and how much it is subject to repeated compression) … the biggest benefit of a latex core is performance and it will feel and perform differently from a polyfoam support core. You can read more about this in post #2 here.
While there is no way to know for certain how long any mattress will last or maintain its comfort and/or support for any particular person or how long it will take before they cross the thresholds between sleeping well on a mattress to sleeping “OK” to tolerating a mattress to finally deciding to replace it because there are too many variables involved that are unique to each person … if a mattress is well inside a suitable comfort/support range and isn’t close to the edge of being too soft when it is new and meets the minimum quality/durability specs that are suggested in the guidelines here then it would be reasonable to expect a useful lifetime in the range of 7 - 10 years and with higher quality and more durable materials like latex or higher density memory foam or polyfoam (in the comfort layers especially) it would likely be in the higher end of the range or even longer.
It’s always more realistic to think of about 10 years as a reasonable expectation for any mattress no matter what the quality or durability of the materials and then treat any additional time after that as “bonus time” because after about 10 years the limiting factor in the useful life of a mattress will often be the changing needs and preferences of the person sleeping on the mattress and even if a mattress is still in relatively good condition after a decade … a mattress that was suitable for someone 10 years earlier may not be the best “match” any longer.
Having said that … if a mattress only uses the highest quality and most durable materials and for people whose needs and preferences or physical condition or body type hasn’t changed much over 10 years then “bonus time” or even “extended bonus time” with more durable materials such as latex, higher density memory foam or polyfoam, natural fibers, or other high quality materials that don’t soften or break down prematurely is much more likely and you will find some people who have slept well on their mattress for several decades but these are the more the exception than the rule.
I look forward to hearing your decision and any follow up evaluations.