I like flipping back and forth in books comparing load data and glancing at calibers I don't even have but If I had to choose one type I would say electronic. It's really nice to be able to fit all of my manuals in my pocket. I can keep all my reloading history and tons of other info in one place that is easy to access. I do have backups and backups of backups for all electronic stuff and I can access it without internet. If my batteries are dead and the power is out I have my books but I will probably just wait so I have good light anyhow.