Very poorly, actually. Unless your car has been tuned to take advantage of higher octane, it can make your car run badly. Octane is really just how resistant the fuel is to burning. Higher octane means more resistant. High compression engines (more compressed fuel is easier to ignite before you want it to), or ones with advanced timing (when the spark plug fires in realtion to where the piston is in the compression stroke) need that resisitance to prevent early combustion.
GW, there are a very few octane boosters that really work, but most are snake oil. "Raises octane by FIVE POINTS!!!!!!!!" screams the label. What they dont tell you is how they define a point.
Its not from 87 to 92. Its 87 to 87.5
On topic, the only place Ive bought race fuel was at MIR for the Neon. And yes, it smells VERY good. I had always though folks saying that were saying that like a gearhead thinks tire smoke smells good, a bad smeel that only happens during cool things.
But no, its really a pleasant smell, %99 of folks would never think its even a fuel smell.