FWIW, I went from HPS to Panther plus's (XP-9's I think, they have since changed there product names from what I gather.). As much as the HPS SUCKED, the Carbotech's where inversely proportionate in *** KICKING.I am stuck on ceramic pads now.
I wouldn't trust HPS on track either. I ran my s13 at HPT once on HPS, running about 7/10th's and was getting pad fade after 10 -15 minutes (luckily each run groups ran 15 - 20 min). I had to let up a couple times, and I wasn't even braking hard.
Have you tried metal masters, EBC (BLEH), porterfield, or any one else, to see if any of them have any track offerings for the j30?