This is a great article and some great views on prototypes and storyboards. I like to create a functional prototype more like a proof of concept, to get an approval on the design, interactivities and other effects like the audio treatment, animation and navigation. This can then be used as a guideline to be followed as far as the design part is concerned. I have always been a storyboard kind of a person, since it allows you to describe the multiple treatments for a scene like the animation, graphics, voiceover script and on screen text. This makes development easier if there is a team of developers. I believe it standardizes the development process to ensure consistency in design.
I think if a team isn't involved, prototyping can be a better way.