I have both a nook and a Sony 650. Both are great readers.
That said, I find myself almost exclusively using the Sony for the following reasons:
1. It's much smaller and lighter than the nook, so it's easier to carry with me.
2. The battery life is also significantly longer (3 weeks as opposed to 1 week).
3. I love the touchscreen interface of the Sony--personally, I find the LCD screen on the nook cumbersome.
4. The dictionary on the Sony is the best I've seen in an e-reader. It's great just to be able to double click on a word and see the definition. On the nook, you have to use the arrows on the lcd screen to navigate to the word you want to look up--or spell out the word completely. And it's impossible to look up a word unless you know the exact spelling. The nook will give you a message along the lines of "word not found" and that's it. On the Sony, you can scroll through the dictionary on screen similar to the way you scroll through a paper dictionary.
5. PDF support on the Sony is much better than the nook. Granted, it's still not perfect.
In my opinion, the only two things the nook has over the Sony is wi-fi (which I rarely use anyway) and price.
Now, as I said earlier, both are great readers. I was perfectly happy with my nook until Sony came out with the 350/650/950 line. I read about all the features and decided even though my nook was in perfectly good shape I was going to get the 650. Bought one about a month after they were released and haven't regretted it one bit.
Good luck with your decision!
dordale
