Things I LOVE about the Reader - it's a lovely design, much prettier than Kindle 1 (although Kindle 2 is better looking than its predecessor). It holds about 160 books. It plays MP3s, so when I'm traveling I can read and listen to books in one device. It uses eInk technology (so does the Kindle) so it's like paper - it won't make your eyes tired like a computer screen. Of course, it's also not "lit" so you can't read it in the dark. Because of the eInk technology, the battery lasts a really long time since it doesn't take any battery power to display a page, only to turn it. I use my Reader mainly for travel, it's so handy to carry multiple books in one small device, rather than a stack of library books.
Things I don't like about the PRS-505 - There is a slight flicker when you turn the page. Since the Reader is only one page, you turn the page a LOT. The flicker bothers me for the first 5 minutes, then I don't notice it anymore. The page forward button is slightly awkward, I think it should be bigger. The next iteration of the Reader - the PRS-700 solves this problem with touch screen technology, you just flick the page to turn it (which is cool, but it wasn't available when I was shopping!). The Reader also doesn't have the Kindle's whispernet connection, so you have to download books to your PC and then transfer them to the Reader (no downloading books from amazon.com on the fly while waiting at the airport, for example). While the Reader can handle a variety of formats (PDF, Word docs, BBeB, ePub) it isn't compatible with amazon.com ebooks and Sony's bookstore has a smaller selection. The PRS-700 adds some other neat features besides touchscreen - virtual keyboard (ability to search, make notes), built-in LED lights (which use a lot of battery power!) and it doubles the storage capacity (up to 320 ebooks).
Other factors:
Cost of ebooks - this is the real limit for me. I simply can not afford my book habit, which is why I use the library almost exclusively and why I only use the Reader when traveling. eBooks are cheaper than real books, but not significantly (I realize that publishers and authors need to be paid for their work, whether a book is paper or digital). Also, you can't easily trade or sell a digital book when you're done.
Book selection - I had wanted to load my Reader up with some of my "go-to" favorites, so no matter where I was I had a some tried-and-true re-readables (Shogun, Lonesome Dove, etc). I was very surprised what wasn't available! Most current stuff is available, but I guess they are slowly digitizing the "classics."
Allinell - I loaded up some of my favorites - Mists of Avalon, Pillars of the Earth and Outlander
*I actually write training materials for Sony products, and have written modules for both the PRS-505 and the PRS-700 so I'm not some weirdo freak who memorizes tons of arcane product facts!!
