I have done the iOS 7.1.2 upgrade in my iPhone 4 recently. My iPhone was pretty stable with the iOS 6.0.1. Due to some mandatory requirement for the OS upgrade I have performed the iOS 7 upgrade. After upgrading my iPhone 4 to iOS 7, I feel there are lot of positives and negatives. The iOS 7 gives new look and feel to the phone but I lost my stability with the phone. Lot of performance issues started with the phone like it won’t respond to our touches as looks like the phone is quite busy. Sometimes the apps are getting crashes.