Look and feel
Physically, not much has changed. The Kindle DX's new shell of gray is pretty appealing, and we definitely prefer it to the white housing of other Kindles. As an added bonus, it seems to boost the contrast ratio on the 9.7-inch screen quite a bit (more on the reading experience in a moment). Like the previous DX, the Graphite version is just about a third of an inch thick, weighs nearly 19 ounces (that's over double the Kindle 2), and stores 3,500 books -- just like the other Kindles. The DX's keyboard is unchanged from the original model and, in our opinions, still pretty abysmal. It is simply not very usable and delivers an awkward, uncomfortable typing experience. The unit is simply too wide, and the layout of the keys too cramped to get much done with it. That said, it's a minor complaint as we've never done a lot of typing with our readers anyways, so we'll be just as happy to never really use this keyboard anyway.
The other physical features -- the rocker and the three buttons (page turn arrows and Home) are exactly the same as on every recent Kindle. The brushed aluminum back feels nice in the hand, with a slight texture to it which makes gripping the device with one hand possible (if not totally comfortable).
Performance and reading experience
The refresh rate on this big boy is improved, too -- but then, where could it have gone but up? E Ink refresh rates simply cannot compete with LCDs or physical books. Our own experience also found that the refresh rate of the Nook (with its latest software update) is now about on par with this new Kindle refresh rate, so it's fair to say that some of the competition is catching up. Regardless, with this unit, we felt enough latency in the refresh rate to be bothered by it, but e-reader enthusiasts or people who really need to travel with an arsenal or reading material are probably more than willing to let that slide in the face of the other advantages.
One problem that was evident in the first generation Kindle DX persists in this model: the orientation sensor is a bit nuts. While reading The Girl with the Dragon Tattoo in bed, almost any time we adjusted ourselves we found the sensor turning to landscape mode. Then again, when we wanted the sensor to kick in, it would do so only about 60 percent of the time, and again you'll see the effects of slow page refresh times of E Ink. Now, you can lock the orientation sensor and pretty much never encounter this issue again (we can't ever really imagine needing to read a text-based book with adjustable font sizes in landscape mode, after all), but it seemed worth mentioning given it goes unchanged since the previous version.
The battery on this thing is what we'd call decent -- it takes quite a while to get a full charge, and lasts about a week of regular use. Amazon says you'll squeeze two weeks out of it with the wireless off, and while we didn't put that to the test, we found the battery life was, as expected, far better with the wireless turned off. You're not going to get the same type of battery life you see out of smaller devices, but for one of this type, it's pretty solid.