Hi mmmmmcoke,
It means that it will stay closer to it’s original specs both in terms of height and in terms of softness/firmness (which is even more important) than other foam materials. Foam softening under the parts of the body that have the most weight is a bigger issue than foam sagging because it isn’t covered by a warranty even though it leads to the loss of comfort and support and is the most common reason a mattress needs to be replaced. There are also other factors involved in the the durability and useful life of a mattress relative to each person that you can read about in post #4 here.
[quote]I basically narrowed it down to the Irving a Medium offset coil mattress and the Macadam a Firm Latax mattress.
The Macadam costs quite a bit more but, if the durability is a big difference I might just swing the extra cost.[/quote]
In almost all cases the support system of a mattress isn’t the weak link of a mattress and it’s the comfort layers that will have a much larger effect on the useable life of your mattress. While there are many different types of innersprings that could be more or less durable if you were sleeping directly on the innerspring … it’s the foam layers on top which are the place to pay the most attention to and it’s not usually the innersprings of a mattress that soften or fail. I would make the choice between a good quality innerspring and a latex support core a matter of preference and not as much a matter of “better or worse”.
The upper layers of the Macadam are latex and the upper layers of the Irving are memory foam and polyfoam which means that the Macadam is much more likely to be the most durable mattress regardless of what type of support system is used underneath the comfort layers.
Phoenix