I've got one. I agree, water in fuel is rare in my experience. But, with a boat and some reserve fuel cans coupled with he latest ethanol separation reports, this funnel makes sense to me. I have used it many times when I transfer fuel. So far, no issues with the receiving vehicle.
There is always a small amount of fuel left in the funnel i dumped it into a glass container and let it sit. No water. So does the funnel work. I needed a new funnel anyway. Don't ask why