This thread made my day.
I've used E10 for 40 years, or ever since it came out, in everything from farm tractors to chain saws, weedeaters, etc. and I can honestly say I've never had a problem I could blame on the ethanol.
I inadvertently let a wheeled string trimmer sit outside all last winter with ethanol in the tank. It started on the second pull this spring and ran perfectly with what was in the tank.
I think a lot of problems are blamed onto ethanol when they're actually caused by something else. Plus there's an endless amount of barroom and coffee shop disinformation going around about ethanol. Someone says E10 will damage two stroke engines because it burns hotter than pure gasoline, another study says ethanol burns cooler. I prefer to believe a credible study.
The owner's manuals for both of my Stihl chain saws simply advise against using gasoline with more then 10% ethanol. So that's what I use in them. They both sat for close to two years while I had back surgery and followup problems. They both started right up this spring on what was in the tank.
And so it goes.