Definitely prefer printed paper.
1. It stays the same. Open book, read, easy-peasy. While e-book formats should be supported forever, look how music has changed - wax cylinders, vinyl platters, 8-track tapes, cassettes, CD's and now MP3 format. I know large corporations would never force their customers to upgrade their equipment, noooo.
2. The Apocalypse. Paper will last, you will have books to read and learn how to rebuild civilization long after batteries have died and wi-fi reception has faded out. And if worse comes to worst, you will always have something not only to read in the outhouse but to wipe yourself with when the reading is done. Which is why most of my books are commercial style paperbacks, no slick glossy pages for me...
