Well there is more to an ebook reader than just reading. The more popular ones have stores for buying books, for example. Of course the UI can be designed for

Well there is more to an ebook reader than just reading. The more popular ones have stores for buying books, for example. Of course the UI can be designed for hardware buttons but at a certain point you're going to have to strike a balance between device size and user friendliness. For example, you could either: not allow text input, have a hardware keyboard, have a software keyboard navigated with minimal hardware buttons, or have a software keyboard with a touch screen. Of those I prefer a touch screen - the device will be smaller and/or have a larger screen and still be user friendly.