I love how easy it is to get new books on my iPad and the selection I have open to me. Living in China trying to get my hands on a book is still really expensive and difficult.
This being said... I still prefer the good ol fashioned paper books. These NEVER run out of batteries!!! I hate being on a twenty-four hour or longer train trip, or a four day transport from China to another country and worry about the amount of battery I have left.