Hi LynnGA,
You can see my comments about the new Saatva Loom & Leaf memory foam mattress in post #2 here.
As you can see they aren’t completely transparent about the quality/density of all the layers in the mattress and the 4 lb density memory foam is convoluted which would reduce the durability of the 4 lb gel memory foam.
While they do have a good return policy … the results of lower quality/density or less durable materials won’t show up in the trial period and would only be apparent over the longer term so I would consider this to be a somewhat risky choice both because of the lack of complete transparency and because of the 2" convoluted layer in upper layers of the mattress which could be a weak link" in the mattress.
Phoenix