Right on, your case is exactly what I had in mind, as far as what it would take to be able to appreciate the diffs. Repeated laps on a track and experience to be able to recognize when it's hooking up differently. Not that those characteristics can't come through in spirited driving, but it takes a lot.If someone is truly chasing tenths or rallying, I would say that those are the ones who should buy the non-pp and then add aftermarket diffs that are suited for what they're doing.
Honestly I'm at the point where I'd want them just because I want them, especially at the price. I mean that's pretty much what getting a car like this boils down to anyway.