Overall, I was shocked by how quickly I forgot that I wasn't reading a book. The screen is perfect - no eye-strain, no problems. The one potentially-annoying hardware flaw is the 'flash' of the screen as each page changes - but I stopped noticing that surprisingly quickly.
I've broken down my thoughts in a traditionally geeky fashion: hardware vs software. And in both areas, the Kindle excels. However, I did have some major problems...
Hardware-wise, there's a lot going for the Kindle. The battery life is great. I read the Kindle constantly all weekend, and never had to charge it. The 'next page' button is on both sides of the device, which is surprisingly useful when 90% of your reading takes place whilst stirring macaroni and/or fending off a cat. The one real flaw is the miniature joystick interface, which is overly fiddly.
From a software perspective, the one-click buying philosophy is fantastic. Books show up on the Kindle in minutes. The extra features (a primitive web browser, 'read to me', etc) are red herrings and not particularly useful. Frustratingly, getting pdfs onto the Kindle is a surprisingly difficult task - one I haven't cracked yet. The automatic conversion service via Amazon doesn't seem to have been rolled out to Europe yet (or I'm getting it wrong).
In fact, I have only two problems with the Kindle - unfortunately, they're both big:
First, the selection of books available internationally is abominable. Roughly, I can find about one in five of the books that I want. Many of these are available on the Kindle in the US, but due to copyright agreements, they aren't out in the UK yet. Which is bizarre - I can buy a hard copy and ship it overseas, but not a digital one. Symptom #1893 of an industry that is rapidly slipping behind the times.
In this case, I wanted to find an appropriate book for my first read on the Kindle. My first thought was Neuromancer (not available). Then anything by Bruce Sterling (not available). Or China Mieville (not available). Then HP Lovecraft (if anything, too available - I was scared off by the 150+ options). Finally, I settled on Richard Morgan's Market Forces.
I suspect the options will get better over time, but, right now, that's frustrating.
My second problem is a personal one. There are extremely few scenarios in which the Kindle is the best 'reading solution'. I can't use it for cheeky previews of American books (see above), I can't use it for proofs (see above) and it isn't cost-effective to use it for reading copies. Market Forces was, if anything, a rare exception - a book that I'd been eager to re-read, but hadn't found a secondhand paperback. And, even then, it was more expensive to buy on the Kindle than through, say, Amazon.
Primarily, I see the Kindle as a device for travel. I'm extremely excited about not having to bring a half-dozen books with me for long plane trips (twice that if I'm connecting through O'Hare). If anything, that means I have space to buy another half-dozen books at my destination... I'm just not sure if that alone justifies the price tag - for both the device and the "books".
Also, Market Forces? Awesome book.