I haven't either, and we've had E10 fuel in Indiana since the late 1980s. The only thing I can think of is that we get a better grade of alky here in Indiana, it's all grown and processed locally.
At the end of 2011 the subsidy for domestic ethanol expired as did the tariff on imported ethanol. Ethanol plants in Indiana are closing up faster than K-marts in the 1990s. I suspect imported Brazilian sugar cane ethanol will be an increasing factor.