The Pogo Sketch finally arrived today.
I should get this out the way first: I've never used a Wacom tablet, so I'm not experienced with drawing "without being able to see", so to speak.
The stylus definitely works with the touchpad, and doesn't require too much force. Without Inklet it's just the same as a finger.
My tests with Inklet were done in Paintbrush, as I don't own any other freehand drawing software. I found that quite often I had to press hard enough that the pad actually clicked before I would get any 'paint', otherwise the cursor would just follow the stylus (that's a feature, remember?), this made it hard to draw fine detail (or a signature). I don't know if it was a problem with the touchpad's accuracy or my own, but it was very difficult to draw on the touchpad.
The main use I would have for this (if it worked well enough) would be for taking down diagrams in lectures. I tried to simulate this by copying a random diagram from some notes: It took considerably longer than by hand (well over a minute) and the result was pretty terrible.
I also tried the stylus out with my iPhone in the 3DS Sketches app. This is the perfect application for the stylus, and it made drawing much easier than by finger. If the rumoured Apple Tablet ever comes out, the Pogo Sketch will be a must-have.
Attached are examples of a diagram drawn on my iPhone with a stylus (right) and using Inklet + stylus (left). By hand was still the best by far.