Originally Posted by polly
You'll be happy to hear that the Sony 350/650/950 use exactly the same screen as the Kindle 3. ...
... with the exception of size. Like your 600, the 650 has the same 6" screen size as a Kindle 3. The 350 has a slightly smaller 5" screen and the 950 a slightly larger 7" screen. All four, the 3 new Sonys and the K3, use the same generation "Pearl" display technology, the best e-ink displays to date and a distinct advance over the generation of the display in the older 600.
You should find the Sonys yield very similar display quality, though I've read comments here that some don't feel that Sony's fonts render as well as the Kindle's. YMMV.