I have NO fondness for E10. Every time they reformulate gasoline, my milage seems to drop. In hot, humid summer weather my 2001 Echo used to get as much as 53 mpg. It has dropped incrementally with gas reformulations so that I'm lucky to get 47 mpg.
And pity the poor folks w/ older small engine equipment. The E10 seems to burn hotter resulting in engine failures.
Then there is the question of energy balance and economics. As an analytical chemist, I'm not convinced that the ethanol (made from corn) displaces any oil usage. Ethanol made from sugar cane is a different matter... but that's a story for another day.
Cheers, Jim