That difference in sound can hardly be placed on the coating / lack of.
If you took 5 crash cymbals, all made in 1992, exact same cymbals as in same line, same model, same size etc, they would most likely all sound different.
That's the real issue about cymbals, IMO. I can't just flat out say I love a Zildjian Sweet Ride (for example), because some don't sound good to me and others sound fantastic.
I have no idea if I like coating or not, because the sonic differences between two of the same model and size can be so different sounding.