Having been to a few of these, I'll give my $0.02:Not a comprehensive list, but still good info.
http://www.motorcycle.com/buyers-gu...o20150917&utm_term=Motorcycle Now Subscribers
I've been to a couple of Rickdiculous days at Thunderhill. The first one I went to, there were literally only 6 or 8 bikes on track. I think they have upped the numbers a little to keep costs down, but it's still waaaay fewer bikes on track than a typical track day or even other riding schools. I had tons of clear track time without traffic, and great 1:1 coaching from Ken and a few other excellent instructors. They followed me with video and then we de-briefed on lines, body position, brake and throttle, etc after every session. I think I cut about 8 seconds off my T-Hill lap times after that first day.