The issue is not the interface, it's the speed--an e-ink display is naturally slower right now. It is a real problem but one due to technology rather than UI.

The issue is not the interface, it's the speed--an e-ink display is naturally slower right now. It is a real problem but one due to technology rather than UI. Coincidentally, on my 3rd-generation Kindle (the one with the keyboard), you can jump by chapters using the left and right arrow keys. This ameliorates going back in most books. Also, Kindles have a nice text search which I've found useful on several occasions. This has also helped somewhat, although it's still lacking overall. Ultimately, I would not want any non-linear books on my Kindle either--I'll stick to pdfs and actual textbooks for now.