Every since the KitKat update on my S4 (Not Mini) my battery life has plummeted. I have turned off Global mode and set it to CDMA/LTE. When I'm in my car with my Bluetooth radio, Hands Free mode pops up twice, even though I've disabled all the features and turned it off multiple times. It turns itself back on. When I use Navigation, which is almost daily, the phone gets really hot and the overheating icon appears. It then starts shutting down applications to "Cool the phone down". Today it tried to shut the phone OFF to cool it down while I was using navigation. I have to hold my phone up to the A/C vent to cool it down so I can use it again. All this happened after the KitKat update. Nothing else has changed. I haven't installed any new apps. The only thing that has changed it KitKat.
KitKat was not tested very well. They say Verizon is always last to release updates because they do extra testing before the release. I'm not believing that one bit.