I've got about 50 books on it, and I love always having something with me to read. I also love the ease of using it one handed, and checking my email from anywhere. As far as I'm concerned, it's better than a book. The biggest downsides are that not everything I want to read is on it yet, and conversely, that it's awful easy to spend a hell of a lot of money browsing. But there's so much cheap content from the public domain that this is not a huge issue.
Arnold Kling has mixed reactions;
It turns out that my reading style is to scan. Sometimes I'll be in the third chapter of a book and start asking myself what the author is getting at. So I'll flip to the conclusion. Or I'll jump ahead to what I think is a more important chapter. Although one can use the Kindle that way, it takes a lot more thought and effort than with a paper book.
My main concern continues to be with what is available on the Kindle. The typical semi-academic nonfiction that I read tends to be unavailable. My guess is that if I stick with the Kindle it will skew my reading in the direction of more popular nonfiction.
I'm not the first one to say this, but it's probably bad to try to replicate an older media experience using a new technology. Instead, if a new device is going to have real impact, it has to be adapted in unexpected ways. For that purpose, the proprietary Kindle format and the closed operating system are its most serious flaws. If it could be hacked, I could imagine it being used for email or blogging. Or it might become a vehicle for new scholarly journals, or cheaper textbooks.
But as a closed system, you have to compare it to book technology. It is easier to purchase, carry, and store books on the Kindle. But it is harder to read them.
Steven Levitt has yet to try;
I’ve never actually read an e-book (after all, I am hopelessly behind when it comes to technology), but this new development is encouraging me to finally try. I would be interested to hear from readers who have tried both the Sony Reader and the Amazon Kindle as to which they prefer.
David Friedman on Kindle
Why Amazon's Kindle is revolutionary
Big Picture on Kindle
The Future of Reading
Kindle is interesting but …
Initial Kindling reactions- Krugman
Experiencing The Endowment Effect
Amazon's e-book reader has clunky design, good performance, and a couple of annoying quirks
So on second thought it seems I should wait around for a while (6 months?) before buying a Kindle.