Hi paddyb,
As you know they don’t say anything about the quality/density of the foam sections or have much information about any of the other materials and components in the mattress so I can’t make any meaningful comments about it in terms of it’s quality or durability.
Zoning systems like they use can be useful and well worth considering for people that have more difficulty finding a mattress with the right “balance” between comfort/pressure relief (under the shoulders especially) and support/alignment (under the hips/pelvis especially) or who have more challenging circumstances or sensitivities, body types that are more difficult to “match” to a mattress, more complex medical issues, or who have a history of having more difficulty in finding a mattress that works well for them. There is more about zoning in this article and in post #11 here and the additional posts it links to. Having the ability to rearrange the zones after a purchase can also be an advantage because it allows you to customize and experiment with different zoning combinations to find the one that works best for you.
On the other side … if the initial few zoning combinations you try don’t work as well as you hoped for then the trial and error process can become somewhat frustrating when expectations of success are high if none of the zoning combinations seem to be a good “match” in terms of comfort, firmness, and PPP.
If the cover is relatively thin and stretchy (rather than quilted) some people may also feel the split between the zones.
Phoenix