Hi Janny,
The 2" polyfoam layer lists two different densities so I don’t know which one it is.
You can see the guidelines I would suggest in post #4 here and as you can see 1.8 would be OK but 1.5 lb would be “on the edge” in terms of thickness/density although it’s underneath the 2" layer of latex which would improve its durability somewhat and it would also depend on your weight and body type. Having said all this … these would be higher quality materials than you would likely find in a mainstream mattress or major brand in the same or even higher price range.
Talalay would have a different “feel” from the Dunlop but they are both good materials. I don’t know what the wool is blended with or the percentage of wool so I really can’t make any comments about this. If it’s blended with polyester fiber then it would be a lower cost material but it probably wouldn’t affect durability.
The density of polyfoam isn’t connected to its support because any density of polyfoam can come in a wide range of firmness levels and your own experience on the mattress is the best way to tell you if the mattress provides good alignment (which needs to be less supportive and “allow” the lighter parts of your body to sink in enough and more supportive and “stop” the heavier parts from sinking in too much).
Phoenix