I have an 06 Corvette C6 with an LS2 engine.
400HP/400LBFT torque.
Suggested to run on premium, but will run on regular with no harm to the engine.

ECU incorporates knock sensors, which will adjust the timing accordingly.
Lower octane will give reduced power, but not that noticeable.

Oddly enough the car will gets 26-30 MPG on the highway at a 65-75MPH cruise and 20-23 MPG all around driving mileage.

The importance of a higher octane and quality gas is primarily in the detergent additives that help the fuel injection system perform at optimum.