Thank you soooo much for the input. This community is awesome!
I have decided to stay with my PRS-505 (my first 'love'.) Unfortunately, I have since found out that my niece, the minx, has recently purchased a Kindle. Sigh....
Not to worry, though. I have decided to send the 600 to my favorite aunt, who is thrilled!!! Her son recently had open heart surgery, and she had to spend a lot of time, just sitting, in the waiting room at the hospital. No more tote bag full of books for her, if, God forbid, she has to endure that again.
I'm just as happy being a favorite niece, as a favorite aunt.