Kurt covered most everything regarding risk/reward points of using a disc sander. You see it used, in most cases on larger models, when you need to remove material that would take you forever and cause you carpel tunnel syndrome if you did it by hand. Typically, long, light strokes along the longitudinal is the practice. The key,
DO NOT STOP MOVING the sander at any point or you will certainly create a low spot defect or void and be on your way to buy a large container of wood filler.
I just don't see the value of using a disc sander on a model of the size in the video. The risk out weighs the reward. Also, it is much, much harder to use on a smaller ship.
With all that said, I do own a small drill I use only for disc sanding and have 5", 3", 2" and 1" discs, along with a multitude of other hand tools used.
I only disc sand when I want to remove material quickly (compared to hand sanding". Intermediate and finish sanding is always done by hand.
My 2 cents.