Hi domiagnew,
You can see the foam quality guidelines I would suggest using in post #4 here.
The upper layers of a mattress are generally the weakest link of the mattress and are the layers where the durability of the materials will play the biggest role. The deeper layers will have much less effect on the durability and useful life of a mattress if there are thicker layers of material above it so if you are in a lower budget range and aren’t in a higher weight range that would tend to compress the deeper support layers “through” the comfort layers more than more average weight ranges then 1.5 lb polyfoam would generally be fine.
Yes they use continuous pour synthetic Dunlop made by Mountaintop Foam.
These are normally questions that it’s best to ask directly when you are talking with them on the phone so that you always have the benefit of the most up to date information but yes … the Freedom mattress comes with soft, medium, and firm layers and the cover is also a different firmness on each side so you would have a total of 12 possible layering and firmness configurations.
Unfortunately the range of mattresses that are available at retailers or manufacturers in each area can be very different and mattresses that are available in some areas are often not available in others. I would make sure that you have called each of them that are reasonably close to you and asked them specifically if they have a latex/polyfoam hybrid available to test because websites often don’t have complete or up to date information.
Phoenix