I have widgets for my calendar, appointments, tasks, emails, etc so I can turn on my phone, quickly check for anything upcoming instead of clicking on one app, pressing the home button, click on another app, press the home button, click on another app, press the home button...
And as Mxbzz mentioned with Google now, a quick swipe and I can check weather, sports, events, news, stock, tracking info, etc all without checking separate individual apps.
The notification system on android is by far more detailed and functional. I just don't understand why apple only allows you to view appointments 24 hours ahead of time in notification center. (Jailbreak and lockinfo is a must if you want a functional NC).