Hi Th3Drizzle,
The comments I believe you are referring to are about a change in the density of the base foam for the Ultimate Dreams latex mattress that happened long ago and don’t refer to a change in the density of the base foam in their gel memory foam hybrid which has always been the same 1.5 lb density. While this is somewhat old information … there is a somewhat misleading negative review that comes up on the top of the “negative” reviews that refers to it so there are still a lot of people who still ask about it.
You can see my thoughts about the change and the review that talks about it in post #2 here and the posts it links to.
The memory foams in each mattress are the same density so they would be closely comparable in terms of durability but I don’t know if they are the same type of memory foam because memory foams that are the same density can still feel and perform very differently from each other (see post #9 here and post #8 here). Outside of any differences in the type of memory foam they both use … the differences would be in the additional 1/2" of 5 lb memory foam, the density of the polyfoam layer in the base, and any differences in the cover.
They would know more about any differences in “feel” between them because every layer of a mattress will affect the feel and performance of all the other layers to some degree and there would be significant differences in how much different people will “feel” any differences between them. Deeper layers will have less effect that most people would “feel” than the layers that are closer to the surface but heavier body types that compress the deeper layers more would probably “feel” any differences more than lighter body types.
The same would generally be true for how they compare in terms of durability. In most cases the upper layers would be the weakest link of a mattress and the deeper layers would have a much less significant effect but with heavier body types (in the low 200’s or more) that would compress the deeper layers more there would be a bigger difference in terms of durability and the useful life of a mattress than there would with lighter body types that would compress the deeper layers much less.
It’s always possible to lift up a mattress with a thicker foundation, with a bunkie board (over a platform bed), or with a relatively low cost layer of ultra firm polyfoam under a mattress. The closer it is to the firmness of the support system (which would generally be a rigid non flexing foundation or platform bed) then the less it would affect the feel of the mattress.
Phoenix