I have, to this point, two levels, and, within each, different grades.
Class A is for the stronger, longer more favored scents, having an intense flavor with day long lasting power. So far only one has made it here.
Class B is for those that almost made the cut for Class A, but are good enough I can't dismiss them as unworthy. They have a solid, moderate to heavy silage with an 8 hour+ life span.