Hi Strummer,
They “should” … but unfortunately in most of the mainstream part of the industry they don’t.
The most basic “quality” information in the case of poyfoam and memory foam is its density (which is usually expressed in lbs/cu ft). With the polyfoam support layer I would be looking for 1.8 lbs and higher (which your mattress seems to meet). In the comfort layers which are usually the weak link of a mattress… I would be looking for 4 lb memory foam or higher unless the price you are paying justifies the use of lower quality materials.
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There are other factors involved in durability as you can see in post #2 here but density is the single most important and basic and is the minimum information I would consider.
You have the advantage of being taller and lighter which means that a mattress will tend to last longer for you (there is less stress placed on the mattress with lighter weights) and the price seems fairly reasonable but your basis for comparison with other mattresses would be different with lower density foams and the “value” in this case isn’t as good as it would be if the density/quality was higher.
I had a nagging feeling that the 4.5 lb density wasn’t right which is why I looked a little further (I normally don’t do much investigation on major brands that have missing information because it usually leads to dead ends and the same lower value conclusion anyway) only to realize that I had discovered this before in another thread here.
You may still decide to buy the mattress of course but I thought you should know that the quality/value is not quite as good as you (or I) would otherwise have believed.
Phoenix