Reading fiction on my Sony Reader PRS-505 is 95% similar (or in many case more pleasant) to reading paper book. It defenitely beats up reading paper back editions that tend to fall apart, have small prints, broken spines etc.
I strongly believe it depends on the ebook reader. If it was kindle I would go back to printed books because of hardware keyboard. The keyboard would destroy the reading environment for me. Also other ebook readers do not have the proper page numbers like Sony ebook Readers, so I would not be able to enjoy reading books on them.
However, when it comes to technical staff. Printed books win hands down.