If their high octane isn't E10 anymore... all the better! Nothing performs as well as pure gasoline... adding ethanol simply allows gas companies to advertise their fuels as being higher octane despite the reduced energy content. Non-ethanol gasoline of the same octane will still give you better economy and more power. (In cases where an ethanol fuel gives you more, it's likely that the pure gas you were using previously was too low octane for your engine).

Besides... like 1D4LV says... if you don't like it... change brands... I don't use Petron or Shell in my Lynx, anymore, and I buy diesel for the Crosswind anywhere I can get it...