Hi jquereau,
Phoenix has a great post on another thread about the first two inches of 5lb. foam on the Costco set being made by Southbay and not being as high quality as the "5lb." may represent. He mentions Ultimate Dreams on Amazon as an alternative that is better made (Tempurpedic Cloud Luxe) imitation but I worry that it will be far too soft. I am looking for medium/firm.
In the Sleep Science ... the top 1" memory foam uses charcoal which would be a "filler" but the density of the 1" layer underneath this is 5lb "without filler". Under this is a 2" layer of medium latex (they don't say the type of latex they use or whether it is blended or natural but I believe that their latex supplier is
Latex Systems in Thailand
which likely means it's natural) and then there is a 7" layer of polyfoam as the base foam. In order to know the quality/value of this mattress I would want to know the type of latex they use and the density of the polyfoam base layer. Without this information it is difficult to make a meaningful comparison in terms of quality or value. They also say that their foam has been third party tested but they don't provide the results or who did the testing.
The Ultimate Dreams Gel foam has thicker layers of memory foam (3" of 4 lb gel foam which is a particulate type) and then 2" of 5 lb memory foam over 8" of 1.5 lb base foam. You can see more information in
post #2 here
about the different types of gel memory foams in terms of "estimated" durability (none have been on the market long enough to know for certain).
If I had to take a guess (and this is all it would be in the absence of more specific information) ... I would guess that the Sleep Science was firmer because you would "go through" the thinner layer of memory foam and feel more of the latex underneath it. Because there is less memory foam in the upper layers ... the latex would also make it a little more resilient.
In terms of the adjustable bed ... Costco doesn't say who makes it so it's difficult to know how it compares to other brands in terms of quality. A split king with massage and remote would normally be in the range of about $1900 and higher (Leggett and Platt S-Cape) so if you take this into account then the "value" of the Costco option for the two together seems to be good although you would be taking a chance on whether the mattress would match your needs and preferences.
Phoenix
