Other than the fact that it looks cool, what is the practical advantage of a flying saucer design exactly? Many types of aircraft can hover. Militarily, this also makes them great targets. The one exception being geo-stationary satellites.
“Other than the fact that it looks cool, what is the practical advantage of a flying saucer design exactly?”
I think the biggest possible advantage would be maneuverability, since you can redirect thrust quickly in many directions. Also, a disc design could remain pretty level moving in any direction, so that could have some uses too I guess.
Or...how about putting a rotating ring around it with a gun mounted on it, so you could target 360 degrees around the ship?
I don't think there is one. The entire notion of saucer-shaped UFOs is based on an error by a reporter. When pilot Kenneth Arnold first reported strange objects flying over Mt. Rainier back in June, 1947, he described an entirely different shape "that flew erratic, like a saucer if you skip it across the water." He said they were not round. But the United Press article implanted the notion of "flying saucers" and within days people betgan "seeing" them all over the world. Never underestimate the power of suggestion!
For a review of what really happened check this out: FLYING SAUCERS?