The Pencil is more like a fat crayon, its latency is absurd, and its palm rejection only sometimes works. After having bought the Pencil and the Pogo, and hating both, I can say that technical drawing on the iPad is simply a poor experience. (Wacom is an example of how to do it well.)

For sketching charcoal/crayon-style they're probably fine, but that's not what's being shown in the video.

Edit: and calling either of these styluses "pressure sensitive" is to diminish the term to nothingness. Wacom is pressure sensitive, these are barely pressure aware. Erratic pressure response, just not very useful.