I think there are grades to everything, and some animals respresent morphs better than others. The biggest variable to this is personal preference. What a breeder considers a high grade and what a customer considers a high grade may be on opposite ends of the pole.

I think the reason pastels are graded are because of the high amount of variability you see in the morph, and how distinguisable a low quality to high quality pastel is. Other morphs are not as easy to pick out, but I think there are low and high quality examples of everything.