Hi there!
I have a Sony PRS-600 and my husband has a Kindle 2. We bought them at the same time and love them! He thinks his is superior, and I think mine is.
The Kindle screen is a little bit smaller than the Sony, but has better contrast and less glare (except in bright sun where I think the Sony is easier to read), as has been said. I like the Touch, he likes the keyboard.
If money is a factor, being able to download library books, easily, as opposed to easily buying every book that appeals could decide you.
. . . That is if you can find a library that will let you borrow and that has enough of the books you want. You might check on that now, before buying.
We listened to the Kindle when he first got it. I would use it if I went blind, but otherwise no.
Good luck!
Fi