I use both kindle, books and audio. I need magnifiers and overlay to read a normal book which can be a pain so that why I like the kindle. When I read I nee to fiddle to focus.
We will have to check out Kindle. So many talk about it these days. As for audio, our oldest son has listened to some books this way, too, but like me, he seems to prefer visual. It is
harder for us to replay a cd book than to reread a page or part of a page. Anthony Robbins though, that self-help guy, used to have audio cassettes I loved listening to growing up. Hearing things this way helped motivate me.