I have a nook and a Sony 650. I gotta say that the Sony is definitely worth the extra $$. I like my nook, but IMO the Sony really has it beat in every way except price and wi-fi access.
Since I never really used the wi-fi on my nook, I don't find myself missing that on the Sony. And for me, the interface of the Sony is much better than the nook.
One thing I really use a lot on my 650 is the dictionary--it's so easy to look up a word--just double tap on the word. On the nook, you have to scroll through the e-ink screen with controls on the lcd screen and it seems to take for ever. And there is no way to look up a word on the nook if you don't know the exact spelling of it. It'll just come up with a "word not found" error. On the Sony, you can scroll backward and forward through the dictionary making it much more functional.
Other pluses include the form factor and weight. The Sony seems to be much more solidly built--and since it doesn't need the extra size for the additional LCD screen, it's quite a bit smaller and lighter.
Another huge plus is the battery life--my nook's battery will die in 3-5 days while the battery on my 650 lasts 3 weeks.
Finally, right now the Sony beats the nook hands down on book organization. It's really a pain to scroll through books on the nook--especially if you side load books from other sources. Now, that might be changing shortly as B&N has announced an updated firmware to be released later this month that will have better organizational options. (Not sure if this will apply to sideloaded books or only downloaded from the B&N store though.)
Good luck with your decision!
dordale
