Bruce,
You are correct. Gasoline these days isn't what it used to be, and a major contributor to it's poor quality is ethanol. It separates from the real gasoline, and starts corroding components. It is also less energy dense, so it provides less power, making our fuel economy worse. Avoid ethanol if you can. I also recommend using a product like "Sta-bil" in fuel systems that are expected to sit for more than a month. It does keep the chemicals from separating.