Hi Dcg,
The issues surrounding organic, natural, safe, and green mattresses are very complex (and confusing) and similar to dietary choices where each person may have very different opinions about “how safe is safe enough for me?” and there may be no clear answers to some very complex questions. A recent reply in post #2 here and the posts it links to may help you clarify what is important to you and some of the differences and “connections” between organic, natural, safe, and green materials and components.
The Silhouette is made by Berkeley Ergonomics and both the BE mattresses and Naturepedic mattresses use high quality and “safe” materials. They both have a component design that provides for good options to customize a mattress before and after a purchase and there are no “weak links” in any of their mattresses. From a quality/durability perspective both of them would make good choices. Post #13 here has more about how I would assess the relative “value” of a mattress purchase when you are making comparisons between mattresses. A forum search on Naturepedic and Berkeley Ergonomics (you can just click both links) will bring up more information and feedback about both of them as well.
The better options and possibilities I’m aware of in the Greater Los Angeles area are listed in post #2 here.
Phoenix