I've more or less decided that the Kobo is not really suitable for reading non-fiction books. Since I (almost) only read non-fiction that makes the Kobo purchase slightly less than ideal.
There are two major problems. The first is footnotes, whether they are at the end of the chapter, or at the end of the book. You just can't directly go and read a footnote when you encounter it in the text.
The second is illustrations. That may be specific to the titles that I've bought and read. But it is really annoying coming across the notes for a diagram or illustration at a random location within a chapter, and then not having the illustrations available at all. Obviously colours cannot be show, but graphs, line drawings, b&w illustrations, and colour pictures shown as black and white should definitely be available. Without the illustrations some books are worthless.