I think the reason they are considered superior is that:
because of the surface tension of the fuel, you never suck air. Even if the "clunk" temporarily comes out of the fuel level (in some manuver), you still get undisturbed fuel. I have heard that you can suck a tank dry and get every last drop with a wet filter.
They are fairly easy to make, and sure provide added piece of mind. I think there was a thread here earlier this year about how to make your own from an auto fuel filter.