I will probably get chewed by Peter again, but I will put in my thought as well on track tire decision.
I guessed if you come across a great deal obtaining track tires, given that you had been driven on the same track and tried to run in the advance groups on street tires, you should be fine start using the R compound. I also waited a full season before I switched to RA1. But it's more because I wear out one of the tires outside prematurely. I was going to flip my street tire side to side, but my tire installer telling me that it's a little bit risky business as he knows I "flied" in my local track, and if the tire blew and I'm in the corner, I'll be done... Anyone else been to my local Track, Pacific Raceway, could confirmed that.
I also seen fair share of people who used R compound too soon, too fast; but then it's all relative, you know some of the new cars ie STi and Elise's OEM tires have grips pretty well closed to R compound's performance.... (and I've seen and heard quite a bit of accidents occured in those cars with newbie)
If you still using OEM brakes or you have extra set of wheels around, the oem 15/16 set up with R compound will be a good choice. (by value). They could be purchased under or around $600. Then depends on the track condition, you could switch them back and forth. I had only tired once by accident, (track organizer invited me to go on the track, while my car is not prepared for track driving at all, ie, full tread street tires, street pad without bleeding... I just went out and enjoyed the ride. Prior that I only driven the RA1 for first time with full tread, and I don't think I was pushing it. Even that I'm not too comfortable driving the street tires already.
