I used some of both during my schooling. I think its personal preference. Its very convenient to not have to carry all those books for sure. There are times when you want to flip between multiple books looking at the same topic from different perspectives. We had a small library in the AA department where most of our books were located if you wanted to look something up manually. When you are traveling your second year for rotations having e-books was a big space saver. I tried to pack light and only carry what I needed to.