Just chiming in to broadcast my MPG and add some thoughts about fuel contamination.
Here in Brazil all gasoline has at least 27.5% ethanol in it by force of law. Regular is 87 octane AKI, premium is 95 octane AKI (and still has at least 27.5% ethanol).
I think this quantity of ethanol hurts the mileage of our vehicles. I'm getting around 35 MPG (US) on my motorcycle, commuting daily at speeds of 50 MPH and below (but sometimes there is no traffic ahead, and the right hand gets itchy...).
Not many Brazilian people around here, but comparing my fuellups with other Bandit and GSX-1250FA owners around the world, I realize I get significantly lower mileage on my moto, and I attribute that to all that alcohol in my fuel.
From this, maybe a tip for those of you who can choose: don't put fuel with ethanol in your bike, or your mileage will suffer.