In my old car I was madly in love with E85, but it had nothing to do with the environment. Had a bit to do with cost (race fuel is about 3x the cost and even premium was always 2$ min higher). Raw power, I was using it as a race fuel alternative and it worked. I was able to run higher PSI on the turbo, the burn rate was better, and the torque increase was enough to toast my clutch in 3 days (I do take most of the blame on that for my right foot)
Haven't had the current vehicle long enough to really make a comment, plus I don't know where to get non-ethanol added gasoline around here. Haven't really paid attention.