I have a 5s with ios 8.3. Was playing with around the cellular data settings between LTE, 3G and 2G (edge) with wifi turned off. I was downtown in a location where I knew was very close to cell towers and the signals are strong. For a while I was unable to get out of 2G mode. I tried everything I knew: Toggle between airplane mode, toggle cellular data switch on/off, power-off phone, hard-reset (power and home buttons). I could not get back to 3G or LTE. It was persistently connecting in 2G with the "E" on the status bar. Finally, after many attempts toggling between the bands in cellular settings, and toggling the cellular data on/off switch in between, I finally got back the LTE connection. Anyone has similar experience?