He said the Penzoil Sychromesh fluid isn't. The Royal Purple is, and so is the AmsOil.
I run the Royal Purple stuff, and didn't notice much of a difference in the way it shifted, but after 60K miles with it, it's still purple and the trans doesn't get hot! Next time I change it, I've been thinking about the AmsOil stuff. See if it makes any difference.
BTW: Synchromesh is just the type of transmisson, i.e. fully synchronized. It's kinda like saying Positrac instead of limited slip.