I went to the source and called Speedplay.

Besides the obvious differences of color and material, he told me that there was an internal difference in the bearings, and that the stainless is similar to the Zero's I'm accustomed to. Also he told me that the stainless is made in house in San Diego. He was a little vague as to where the chrome moly are made, but used the word "outsourcing".

I think I'll pay the premium and go with the stainless.