The problems in this video are exactly the problems I face.
The only place I had a problem with the solution was the idea that drawing on a tablet is the same as drawing on paper. For me, it's just not. My dream solution would let me draw on paper to begin with.
That said, the solution here still looks better than trying to develop ideas in Visio/Omnigraffle/Axure/InDesign/Keynote/whatever by orders of magnitude.
I'm very excited to try this out.