Carrier Settings upgrade caused my LTE to drop to 3G
Updating my version LTE iPad's carrier settings caused my network to drop from LTE to 3G on the spot. Turning cellular data off and then on didn't help, turning my LTE off and on didn't help. Restarting didn't help. I had to reset my device to factory settings and then re-activate it as a new device. Then I would instantly get LTE back. I'm going to avoid accepting any 'carrier settings' updates from now on. Just chose "Cancel"!
iPad (3rd gen) Wi-Fi + Cellular (VZ), iOS 6.1.1