Hi goneagain,
In general this is true but it would also depend on the specific polyfoam and spec you were comparing. there are some polyfoams that come close or in some cases surpass some of the individual specs of some types of latex and of course they are less costly but overall if you take all of the specs together then latex would be a superior material.
Latex is the oldest type of foam material in the industry but because of its expense and because it’s not as “proprietary” and able to be marketed as an “exclusive” material and because of the focus of most of the major manufacturers who dominate the industry on lower quality higher profit materials that are sold on “showroom feel” alone … it is not as easily available in the mainstream market although it is widely available from smaller or independent manufacturers. Post #4 here is connected to this and the lack of good information that is generally available in the mainstream market.
As you can see in post #4 here … durability is a complex and “relative” issue and is connected to the gradual loss of firmness and other properties of a foam that reaches a point of producing discomfort or “symptoms” for the people sleeping on a mattress rather than the material collapsing or breaking down completely. By most definitions of durability though, latex as a category would outlast HR polyfoam and have higher performance in the specs that mean the most.
Yes … this is very true because like any material … some people may feel very differently about it and how it feels and performs than others.
Have you tried calling Rocky Mountain Mattress?
Latex is certainly the most resilient of the foams but resilience and firmness are very different things. Latex is also very “point elastic” which means that it takes on the shape of the body more exactly than other foams which can make it feel softer (even in firmer versions) and the ILD of latex is also measured differently than polyfoam (on a 6" core instead of a 4" core) so the listed ILD would be softer than the equivalent in polyfoam. Some of the other specs that contribute to perceived firmness such as compression modulus would be higher so this would make it feel firmer. Dunlop would feel firmer than the equivalent ILD in Talalay because of this. You can read a bit more about this "ILD / IFD difference between polyfoam and latex in post #6 here.
Koosh is just a proprietary name for HR polyfoam used by Foamite. You would need to talk with them about any specs you wanted but a forum search on Koosh (you can just click this) will bring up a little more information and some feedback about it (once you scan past the name of one of the forum members that has “koosh” in their membername).
Phoenix