Ethanol has half the energy content of gasoline, so you need to burn twice as much for the same level of power.
Naturally they won't charge you half the cost of gasoline for a gallon of ethanol, so your wallet gets hit harder at the fuel pump with ethanol blended fuels.
Ethanol absorbs moisture in the air, so you can't afford to leave your bike sitting unused if you have an ethanol blend in your fuel tank.
and
i hear that ethanol use requires the engine to have special ethanol compatible seals.
If you run ethanol blended fuel after running an engine jetted for straight gasoline, you need to rejet the carburettor to make allowance for the extra fuel flow required to achieve correct air/fuel ratio. If this is not done, the engine will run lean, and consequently it will run significantly hotter, and with less power.