I think the problem of having to write larger than normal is mostly due to the lack of friction between the pencil and the screen. (To a lesser degree it might also be due to the not so sharp tip of the pencil.) The same issue exists for drawing. Because there’s less friction, there’s less control, and therefore an inability to get small detail, and therefore a need to zoom in and out, which puts a big damper on workflow. There are some screen films that are supposed to improve friction, but I believe the better they do so the more they compromise screen clarity, and I have yet to find a screen film that provides friction as good as real pencil and paper. I’m really hoping Apple provides a solution in a future iteration of the iPad and pencil that gets it close to pencil/paper feel while retaining screen clarity.