Hi brass,
I share many of your thoughts about Chinese or other offshore suppliers and manufacturers and the pros and cons of a developing “global market” (see post #6 here and post #2 here).
Just for reference … there are currently over 500 mattress manufacturers in the US with one or more employees and a few hundred more in Canada. The top 16 and more information about their market share and their level of transparency are in this article. There is also more in post #404 here and post #12 here about some of the differences between the major manufacturers and the smaller local and regional manufacturers and better sleep shops that are quietly building and/or selling better quality/value mattresses in most areas of the country (or in some cases online).
Phoenix