I'm not so sure the type of plastic has all that much to do with how it flies. I have three DX Leopards. (I know, long story) They were all purchased new but at different times and from different sources so it's unlikely they were from the same production run, but they are still all the same plastic, same mold, same stamp.
The oldest one is the most beat in and it will fly mostly straight with a slight right fade until it slows down and then it drops off to the left. It also flies the farthest of the three.
The second one flies straight until it loses speed and then it fades hard right.
The third, and newest one, turns hard left right off the tee.
I try to always throw them the same but, being human, I am the inconsistency in the equation.