I wonder if this perception of scale has to do with the perception of silver particles floating on the top of the clear gelatin emulsion?

I think that platinum seems to favor an image with a certain type of tonal scale, perhaps that could be described as 'long midtones'. Azo/amidol seems to favor images with a prevelance of 'top notes'.
Sorry for the dogy terminology.. talking about photography is always difficult.

--Aaron