Hi bcronan,
Welcome to the Mattress Forum! 
I see that you’ve registered with your email address, which means that spambots can acquire that are they monitor this site, so you may wish to change your user name.
There are updated specs for Dromma on the simplified choice thread here. The 1.5" top layer is blended Dunlop from Mountaintop. The middle 2.5" memory foam layer is 4 lb, and the polyfoam core is 1.8 lb. This material would be adequate for most individuals, but I would provide a caution for those in a slightly higher BMI because of the 4 lb memory foam (5 lb would be preferable) combined with the 1.8 lb polyfoam core.
There are many factors involved in the durability of a mattress or the components in it and there is more information about that here.
Phoenix