I would disagree strongly with this. :)

The e-reader UI is generally so much better than paper, if a book is not available for kindle, I'll usually find something else to read. Pale Fire is a special case book where you want two have bookmarks where you are currently working. I read Chuck Palahniuk's Diary on paper, and an e-reader would definitely have ruined it.

Technical books with a lot of charts, diagrams, monospaced code examples, etc can highlight the weaknesses of e-readers. PDFs are almost always better on a tablet.

But for like, words-in-a-row novels that don't mind being re-wrapped, there is no comparison, for me. e-Reader every time.