I've had the S4 since Thursday. I've had to reset this phone at least once a day to get internet access back. Even while connected to a WiFi network, my phone randomly stops connecting to the internet at some point midday. The play store and browsers stop working. The only way to bring it back is to either restart the phone or flip airplane mode on and off.
Is there a reason for this behavior? Recently I've used an iPhone 5 and an HTC 8X, neither devices had this problem.