I myself really enjoy index racing and I have been moderately successful at it I have a 10.90-11-00 car slowed down to run 11.50s via a throttle stop. My home track doesn't offer it so I have to travel two hours to run but its worth it. An advantage at most of the tracks I run at is you can run two classes : your index class ( 8.50. 10.00 or 11.50 ) and also Pro Dial which is basically a bracket / dial in class ran on a 5/10s pro tree. I prefer the 5/10s pro tree to the full tree and will probably be gearing my future racing to more of it.