[wolrah]

e-ink displays look to your eyes basically like paper. I absolutely love my Kindle for reading books.

For papers though, not so much. The screen is too small for a layout format like PDF to work. The document has to be able to reflow for the screen like a proper e-book to work really well, and PDFs don't. I've heard the Kindle DX was great but those haven't been made in a while, otherwise there's a few big ones Sony made which are apparently awesome but expensive.