This review will be short and sweet. I like practically everything about this device. It's light, it's fairly tough, it's intuitive, the battery lasts forever, it holds thousands of books, and most importantly it's very easy to read. I've read three books on it so far and it's pretty much identical to paper. I find computer screens a bit taxing after a couple hours, but the e-ink technology makes for excellent contrast and the lack of backlighting is very easy on the eyes. The pdf support is a trifle rickety, but especially as you can switch the layout from portrait to landscape it's possible to get reasonable font size even on small scanned pdfs.
Calibre works very well for me.) Certain features cannot be unlocked until the Kindle is registered, but I can't register it yet as I don't have Wi-Fi. Regardless, these are minor issues, and they mostly irritate me as they're likely to affect only those that would have bought from Amazon anyway. Overall, highly recommended. I may never buy another normal book.