The only thing I like about them is the convenience. Other than that, I'd much rather have a book in hands.
they also usually cost less than buying the book and more money from ebooks goes to the author than they would get from a hard copy sold. All around bonus for the author and the reader.
The only way greedy ass publishers are going to survive in the coming years is to stop screwing writers out of their fair share. The days of them giving a couple pennies per book sold to the author are over--even shitty authors selling online are making more than that.