I like the Calcutta, Our two semi local tracks run a Dialing for Dollars pot.
Based on the last TT.
It seems like they are different. One can be closest to dial, the other is best package.
The buy backs are a big deal ,too.
I had a buddy that raced at a low car count race do his second round buy back for $25 and put him in the semi with $50 pay out.
http://www.thunderroadracewaypark.com/payout.html
http://www.prescottraceway.net/ (click on entry fees in the left hand box for pay outs)