AP1 is more affordable and there are more of them. You need to qualify "track car" to mean either a car that gets taken to the track occasionally or one which lives there. I think you will find the majority of full track cars to be AP1 for economic reasons. The reality is that incremental performance improvements have far less meaning to track people as the the number #1 problem facing track people is not performance but funding. It boils down to dollars. Posers don't worry so much about it because they simply buy something and use it for some time like brakes. A poser might buy $800 in rotors 'cause they look nice and are "higher performance" but a tracker would look at them and say "they cost how much?" knowing they would last 2 months tops on the track. Same goes for BBKs. It's not so much how good the brakes are but how much of your budget you are willing to part with to stop quicker.

 

ap1 for me

even if i could afford an ap2 i think i would still go ap1 out of personal preference