Troy, I came to the same conclusion. I found a local Gate station selling ethanol free 91 octane. It was 4.15/gallon vs 3.75/gallon for E10 89. I ran three tankfuls and saw no improvement in mpg at all.
2012 Race Red 5-door SE, 18" Ti wheels, Ti headlights/fog bezels, 20% tint, debadged trunk
2002 Sonic Blue SVT - supercharged (sold)
2008 Vista Blue SE (gone)