Reference: Baker, EA, and Lee, T.S. "Long Term Corrosion Behavior of Various Stainless Steels" ASTM Symposium of Degration of materials in the Atmosphere. Philadelphia, PA, May 12-15, 1986.
Qs Products are all made from 304 grade stainless steel, which, as you can see from the above table, has the highest resistance to corrosion, along with 316 and 316L.
The staining character and pit density difference between 304 and 316 is negligible and does not, in our opinion, justify the 20 - 30 percent price difference.
Directly under purchase, satin stainless steel has a tendency to slightly discolour. This is caused by the oxidisation of the residue of the buffing wax left on the finished surface.
Once this has been cleaned by a non-abrasive cleaner (we recommend Handy Andy), the finish will maintain itself with just the occasional clean.