So I checked some Japanese sites (long live webpage translators!) and the SMT 6806Z is a chrome steel bearing you can buy in Japan for 8€.

At Boca bearings a chrome steel bearing retails at 29.95$, stainless steel at 49.95$. The AKN bearing is stainless steel as well so indeed that should be higher quality.

I am curious to see in our application what difference this will make in lifetime.

Volkert