>How accurate are the sketches?
In general, sketches with Inkling will be accurate to within approximately +/- 0.1 inches (+/- 2.5 mm) in the main drawing area of an A4 page, and within (approximately +/- 0.2 inches (+/- 5.0 mm) at the edges of the page.
2.5mm is quite a large fuzz factor. Enough to make me think this could be great for very-rough sketching / outlining of a design, but not enough for replacing scanning / doing (essentially) OCR.