it's disconcerting to hear that you're relatively disappointed in the T1-R's. I was considering getting a set next.
I currently have the T1-S's, and I've been pretty pleased with them. I have never tracked my car and do mostly local/city driving, but the T1-S's have been good all around tires. Their sidewalls are a little soft, and I thought the new T1-R's supposedly addressed that shortcoming.
As for your tire pressure settings, what size are you running? 30psi sounds pretty low, so I assume some sort of 16"?? Also, a 5psi variation is pretty huge. Most people I know run maybe 2-3psi lower in the rear.
FWIW, I'm on 18x7.5" VOLK LE-37T's w/225-35-18 T1-S's and 47psi front 44psi rear.