It loves water, like it attracts it. Fex fuel using E85 gets poor mpg. In racing, mpg is not an issue, but it can make big power. One reason in race engines, it cools the air at intake due to the evaporation cooling MUCH higher than gasoline, and the engine uses much more volume for chilling the air charge. It also contains some oxygen. Cold air is more dense, so the engine can get more in the combustion chamber.Ethanol is fantastic if you want to make big power on a fast street car (the octane rating approaches that of most race fuels at a much lower price), but yeah, in regular gas blends I'm not a big fan. I get why they do it, but at the end of the day its just a corn subsidy. There's no way it makes sense from a carbon neutral perspective, you have to farm the ethanol using diesel, transport it using diesel, etc.
I suppose from the perspective of your fuel system and engine, ethanol is actually a really excellent fuel system cleaner. It's harder on plastics and rubber seals over time though.
Street cars, it is just OK. They are designed to run it. I might try E-85 in my Buick some time as it is flex fuel, but stations here do not carry it.