I prefer paper planner when it comes to school work. I can look at something on my phone and get distracted easily so then I forget. With a paper planner I can keep up with everything. I am also more likely to use it since I paid for it and don't want it to go to waste.
I use online calendar, which I have the app that can be used as a planner too. It does have the sync option in which I can transfer all my notes and journals to my e-mail address or to Evernote. I have found it's convenient for me because I carry my smartphone everyday, which I would do all the planning and schedule using the online calendar on my phone. I have found it's much easier for me than carrying a physical planner.
An electronic planner/calendar works for me, but I don't like the idea of having one online. Some of the material entered into a calendar might be a bit sensitive if a site hosting an online calendar were hacked. Someone knowing when I am out of the house, for example, could be a problem. Information on medical appointments might get out there or anything similar. While my life is not usually that interesting that stealing calendar information would be of much use to anyone, I would not want my appointments with client names getting released.
