Me and vince over at trifecta basically worked on the same principal with e85 as you would with methanol.. they are both fuel with higher octane level. The main benefit would be to kill detonation or prevent it all together. If you was to do something like this than I would say to go with e85 as it can be alot more efficient if your local area has it at the pump. The benefit on our n/a v6 camaro with stock internal is around 7.5% to the rear wheels at peak over gasoline and this is after maxing out MBT and even tuning out VVT cam phasing to take complete advantage of e85's high octane, but the greater benefit is full torque@3k rpm and off peak power/torque which is alot higher. We worked out some more bugs since my last dyno so I think we should be able to see a little more power/torque on my next dyno session.
Where meth/e85 really shine is with turbo induced enignes. Ask those turbo guys running e85/meth if they will ever go back to gas and they will probably laugh at you lol. The gain is tremendous.