I've been trying few different blends for the past 2 years now.
tried E10, E25, E50 and E90
when running ethanol you need to be sure your full fuel system will cope with alcool
an easy upgrade is to fit injectors 30% bigger on your car, you'll be able to drive your car straight away with E85 without any mapping needed... if your car has standard injector, just need to fit 380cc injectors and you are ready to go, or you could use 360cc with a higher fuel regulator pressure
I tried the last option and worked just great... (of course you'll get even better results if you remap your car)
I'm now running with Aquamist water/alcool injection