Will everybody forget about ping or knock or preignition? In a modern engine that will only happen if one of the control components is defective or if carbon build up in the combustion chamber glows red hot and ignites the fuel charge before the spark fires.
A couple of years ago "Car & Driver" magazine tested several cars on a dyno. They found that using regular in an engine designed for premium gas resulted in less power, higher consumption, no fuel cost savings, and no problems. Using premium in an engine designed for regular resulted in no power increase, no consumption changes, no problems, and a waste of money.
lexus114, try each type of fuel for at least three repeatable tankfuls each, figure your total fuel cost per mile (not just miles per gallon), note the driving feel, and decide which fuel you prefer.