Its true that ethanol has higher octane, but it has way fewer BTUs. If you run 110 octane tuned for gasoline, you'll make MUCH more power than if you ran alcohol.
Tests are rampant on the internet; people who have switched from 9:1 on pump gas to 11:1 on alcohol and the power output stayed the same.
Bottom line is you will need a certain level of octane to support your engine's parameters. Why not choose the fuel with 20% more BTUs?