Hi Astraeus,
Innersprings absorb less energy than a polyfoam support core, which means they are more resilient. This means that an innerspring mattress will be more “springy” than polyfoams and those who have tried both will validate that the feel between them and how they each react to motion is very different. Some prefer one while other prefer the other. Both can make high quality support layers.
There is also a property called “point elasticity” which is the ability of a material to compress without affecting the areas beside it. Because of it’s elasticity … there are millions of points that can compress individually and which only affect small areas around it. Polyfoam will not be as point elastic as latex. Innersprings on the other hand have less “point elasticity” than both of those items. Their ability to take on a body shape and isolate motion is more limited to the number of coils and how the coils are connected to each other. Pocket coils with a high coil count would be the most “point elastic” of the innerspring types.
An innerspring unit will tend to be more durable than a high-density polyfoam support core, but neither are usually the weak link within a mattress.
All of this of course can be modified by the layers both above and below a particular component or material.
There are so many differences between them that it is really impossible to answer these types of “apples to oranges” questions in any other way than through very general comparisons that may not represent the differences between two specific support materials. There are those whose “ideal” mattress is latex over innersprings for example and not only that, it may be a particular type of innerspring. There are others who will only sleep on latex using a polyfoam support core. Others prefer all latex.
There are many other more technical differences but the most important differences are the ones you can feel. Either of them can make a good choice for a support layer and in the end it really boils down to which one you tend to prefer. Both of them can provide good/support alignment. There are so many varieties of both that it’s not really possible to make more specific comparisons outside of some of the more obvious and more “generic” differences that I’ve mentioned.
In essence … all mattresses boil down to what I call PPP which is their Pressure relieving qualities (that comes from the pressure relieving cradle that they form which spreads weight out over the mattress surface), the Posture and alignment qualities (this is the ability of a mattress to “allow” your wider lighter areas like shoulders to sink in enough while “stopping” the heavier narrower areas like the pelvis from sinking in too far) which keeps your spine in alignment in all your sleeping positions, and the Preference qualities (which are things that are more subjective or preference based like springiness, energy absorption, breathability, being more “on” or “in” the mattress, the surface or “hand” feel of the mattress, motion isolation, slower or faster response, and others).
So there are many complex differences even within each category much less the differences between an innerspring and a polyfoam support layer that the best way to decide is to make sure that they both provide the pressure relief and alignment you need and then everything else after that is preference and the relative “value” of each material compared to the price of the mattress.
As you’re probably already aware, both Dreamfoam and Arizona Premium are site members here, which means that I think highly of them, and both of the mattresses you’re considering use good quality and durable materials. Both can also be had in quite firm configurations.
While all of the layers within a mattress work in unison to provide overall comfort, having the 6" of latex versus the 3" in the Ultimate Hybrid will have a different feel, effectively doubling the comfort cradle in your uppermost comfort layers. The concern would be to make sure that you are not sinking in too deeply, as you do spend time in the prone position. With either item, I’d recommend a phone conversation with the manufacturer for their advice on which firm configurations they’d recommend for your BMI and sleeping style.
Phoenix