I love that it can be used as an appointment reminder, event planner or to-do list manager! It also has some nice features like recurring events where you only have one reminder instead of having many separate reminders every time there's something scheduled in your schedule.
I wish they had more options for color schemes but otherwise this program does everything we need from managing our schedules. We're using busycal primarily as scheduling tool so far everyone likes how easy it makes adding appointments/scheduling meetings very quick with little effort required during setup.