I think the waters have been muddied somewhat recently by the invention of "Pro Performance" willow. Which seems to be any willow with a low density and/or better "Ping"Density is a fact. "Ping" is subjective.I'd prefer we just went to Pro (Lightweight), G1 (Perfect grain structure) G2 (Minor blemishes, graping, pin knots) G3 (substantial blemishes etc) Butterfly.
It's @The Doctor I think @sarg