I run a small landscaping service. The ethanol mix gas does ruin carburetors and can essentially melt the "standard" rubber fuel lines - IF you let the equipment sit for extended periods between use, such as leaf vacuums that only get used in the fall or mowers that aren't used in the winter (I'm up here in New England).
Most local small engine repairs shops in my area have large signs stating that NO warranties cover fuel-related engine damage.
I am a member of my local volunteer fire department. We have been fixing and replacing small engines the last few years (water pumps, chain saws, generators, etc) that have been damaged by ethanol fuel. A lot of the FD equipment doesn't get used constantly, but has to be ready instantly when needed. We have had to switch to special extended storage fuel to put in our equipment, "Tool Fuel", that runs around $20+ PER GALLON. This is bulk pricing - this fuel can be $15 PER QUART in your local hardware store. This is one reason your fire department has been asking for more money at budget time.
Some of the newest equipment coming out has ethanol resistant engine parts, but a lot doesn't, and it can be hard to tell which is which.
I wonder what kind of environmental impact there has been from throwing away equipment ruined by ethanol (which ran fine previously, and could last for decades longer with good fuel), and having factories build new more expensive equipment that can survive the new fuel.
I am just going by what I have experienced with ethanol mix fuels.
