My experience with E10 goes back to 1987. I had a Chevy Sprint with a Suzuki 1000 cc engine (solid lifters). It was purchased due to the advertised 50 mpg, and then I had 70 mile daily commute. Gas mileage on the little car was checked MANY times, and it was always 49 mpg. I even removed all but the drivers seat and a did a few other weight saving mods, along with ultra conservative driving technique, to see if it would improve mileage, but it remained 49 mpg.
E10 was being offered in KS about that time. I jumped on it to keep a few bucks from going offshore. Mileage dropped to 46 mpg. No more E10.
Fast forward to recent times. I have a fuel cell with a rubber seal on the inlet. It has dissolved. Rubber remnants can still be seen floating in the bottom of the tank.
Some of my gas line is neoprene. It becomes ridgid, hard, in one year. An easy comparison can be made between it and the pliable neoprene line of my PCV setup.
Autolite carbs are my choice. Planned replacement of float needle, accelerator pump, and power valve is now each 2 years, and that with a complete emptying of carb over the winter.
I hate E10. A ripoff, and poor fuel. With the added expense of good gas, I try to run 100% everyother fill.