Alky vs. Race gas

Talking to a friend of mine who owns a race shop we got into a debate about alky vs. gas in big cubic inch engines. He stated that because of the slower burn of alcohol, in big cubic inch engines gas makes more horsepower, because of the faster burn. He believes that with alcohol the piston moves faster then the flame can travel and therefore you don't get the full burn of the fuel. In essence the piston runs away from the fuel burn, therefore you aren't getting the "push" from the power stroke.
Now I see a lot of big engines all running alky and have to wonder is his theory wrong. Or do you sacrifice some power to get the benefit of the much cooler temps. running alcohol.
I know in my go-karting days, we made more power with race gas but the cylinder head temperatures would wipe out the rings. So we ran the white stuff.

None of the fastest machines on the planet use gasoline.