Hi eeks,
As you know the BME is a “finished” mattress and has a great trial and return policy so you can test the mattress in your bedroom instead of a showroom to make sure it’s a good “match” for you in terms of comfort, firmness, and PPP without any risk.
The SleepEZ on the other hand is a component mattress which allows you to fine tune the comfort and/or support of the mattress by rearranging the layers or exchanging a layer after a purchase at a minimal $30 cost. They also have a good return policy that allows you to return the mattress for a refund for a $99 cost. You can also replace a single layer if one of the layers softens or breaks down sooner than the others (usually the top layer) or if your needs or preferences change over time without having to replace the entire mattress.
There is more about the pros and cons of a component mattress with a zip cover and loose layers vs a finished mattress with glued layers in post #15 here and post #2 here.
There is also more about the pros and cons of a latex/polyfoam hybrid vs an all latex mattress in post #2 here.
Both of them would certainly make great quality/value choices.
Synthetic rubber (latex) is made from a copolymer of styrene and butadiene. There is more about the different types and blends of latex in post #6 here.
Any type or blend of latex is a very durable material relative to other types of foam material such as memory foam or polyfoam.
All the latex you are likely to encounter (either Dunlop or Talalay that is made with either natural or synthetic rubber or a blend of both) will have a reliable certification such as Oeko-Tex, Eco-Institut, or Greenguard Gold (see post #2 here) or C2C (see post #13 here) and based on actual testing I would consider any type or blend of latex to be a very “safe” material in terms of harmful substances and VOC’s (offgassing).
Both the blended Talalay and the synthetic continuous pour Dunlop in the BME are certified for harmful substances and VOC’s by Oeko-Tex.
There is more about soy foams or other so called “plant based” foams in post #2 here. They are basically the same as any other polyurethane foam and I would make durability comparisons between any type of polyfoam based on their density. The polyfoam in their base layer is 2 lb density which is a durable material that would be suitable for any weight range. All of their polyfoam is also CertiPUR certified for harmful substances and VOC’s…
Neither one of the mattresses you are considering have any lower quality materials or weak links that would compromise the durability and useful life of either mattress relative to any weight range.
There is more about the 3 most important parts of the “value” of a mattress purchase in post #13 here 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 suitability, durability, and all the other parts of your personal value equation that are most important to you (including the price of course and the options you have available after a purchase if your choice doesn’t turn out as well as you hoped for).
Once you have narrowed down your options to a list of finalists that are all choices between “good and good” (which they are) and you have confirmed that none of them have any lower quality materials or “weak links” in their design relative to your weight range (which they don’t) and if at this point there are no clear winners between them (which is usually a good indication that you have done some good research) then you are in the fortunate position that any of them would likely be a suitable choice and post #2 here can help you make a final choice based on your local testing or mattresses you have slept well on, your more detailed conversations with each of them, your confidence about PPP and the suitability of each one, their prices, your preferences for different types of materials (or different types and blends of latex), the options you have after a purchase to fine tune the mattress or exchange or return the mattress or individual layers, any additional extras that are part of each purchase, and on “informed best judgement” based on all the other objective, subjective, and intangible parts of your personal value equation that are most important to you.
Phoenix