I agree about the uselessness of the widest margin setting. Why on earth did they make that a choice? I can't see anyone ever using it.
My Paperwhite is my favorite Kindle so far, which is to say, I like it better than my Kindle 3 (keyboard) models. It is light years ahead of my first ebook reader, ebookwise 1150. I think I like it better than every other ereader I have tried.