I have 4s and I turned it off maybe a week after I got the phone, I like the phone itself btw. It just makes too many mistakes and cant understand pronunciation of the last names of half the people on my contact list. Reminder and calendar are the only features that it worked ok for me.

But for calendar I usually want to see my calendar before making appointment so the only case where I was using it time to time was when cooking something and needing a timer, but then I realized I have a $5 timer in the kitchen that works better and faster to set.