Yes, I think it is a great way to enforce reading. It is also up-to-date technology which is always important to have in the classroom.
I think it would be more efficient. It might save costs as the years go by! Upon first buy it would probably seem like a lot to put down on books, but I believe it would end up saying money in the end! would also diminish messy book rooms.
I believe it would be better for many reasons. One of them is the fact that it will be cheaper than having to buy textbooks. It would also be much more convenient as far as having it all in one place. If you use iPads you can also read your textbook and respond to homework or a forum all on the same device by just switching tabs!
I think that there needs to be a good combination of both! There's nothing like having an actual book in your hands, but the great things about e-books is that there are many interactive options with it. For example, the book can read itself aloud for students who comprehend better by hearing, but I do not think we should ever extinguish paper books in the classroom!