Photos: Heather BeschizzaWere it not for its price, Amazon's Kindle DX would render the older models obsolete: the standard model might be a better form factor for reading novels, but the DX's huge display and relatively small bezel and keyboard make it more attractive, more readable and better able to present large documents. Native PDF support (there's no zooming) deprives Sony's Reader of its last technical advantage over the Kindle lineup. At the new size, the Kindle looks well-designed, simple, even sexy: a third of an inch thick, it has 3G wireless access to the Kindle Store, 16 shades of gray, 3.3GB of storage, auto-rotation, text-to-speech (if permitted by the publisher) and the experimental web browser. For those who just buy books and mags, and who don't plan on reading stuff from their computer, the DX's combination of best-of-class hardware and Amazon's well-stocked store make it the one to own. For the rest of us, however, its format support remains a pain: if you don't like PDF or plain text, you're tied up in an irritating file conversion service: at $480, the DX is quite expensive enough. If you're not sure about it because of the bigger size, check out our gallery of the Kindle DX alongside everyday items. Though based on the Kindle 2, it's the first version that seems a beautiful thing. Update: Testing PDF for speed and compatibility, I tried a 2.4MB PDF of "All you can eat: autophagy in neurogeneration of neuroprotection," by Phillipp Jaeger and Tony Wyss-Coray. It loaded in 3-4 seconds, with 1 second transitions between pages -- same as plain text! Nothing in the document confused it, layout was good, including charts, pictures, superscript and greek letters, etc. Hilbert's Foundations of Geometry, full of pointy-headed Tex-set equations, was just as snappy.