From what I can gather on info, cost and power aside (power, which is really not aside it's the reason Lol) I hear there are a lot of consistency issues with E85. Meaning gas is gas so to speak anywhere you buy it but E85 can be 65,75 etc. If that's true isn't there be a huge risk of grenading the engine if tuned on a "good" batch then you get a weak batch and don't know it?
There are many ways to address this concern, one way to test the fuel before you fill up, the tester is a graduated tube that costs under $ 10.00. The other way to run a flex tune that automatically adjusts the tune based on readings from the 02 sensors.
E85, E98, Ignite Red just makes more power than race gasoline period and the fuel is much cheaper than race gasoline. Those who disagree do not have quicker time slips, the track does not lie.
AJ, which is a diehard leaded race gasoline tuner, just went 9.58 in a stock boost Demon. What fuel was he using? E85, he finally gave up with the race gasoline and now is running E85, what does that tell you? What did his Demon run with race gasoline, 9.98. I am not making this up, ask AJ.