Don't misconstrue, but I go both ways — I'm a bi e-reader user.
My e-book reading odyssey began with the Kindle. Then I started using the Kindle app on my iPhone. I then moved to the second generation Kindle, then to the Kindle and iBook apps on the iPad.
I have now returned to a dedicated e-reader, the new Kobo eReader Touch Edition, switching with the Kindle and the iPad Kindle app where I have most of my unread books. As soon as I finish reading my pending Kindle books, I believe I will stay with Kobo.
While not exactly typical, I believe I'm not alone in my tablet v. dedicated e-book reader vacillation.