I have an AT&T iPhone 5 - i've noticed that it intermittently drops service completely or goes from LTE to 4G at random times. At first I thought this was normal, but my girlfriend recently got an AT&T iPhone 5 and hers does not exhibit this issue. In fact, we were on the bus this weekend and i pulled out my phone to see that my service had dropped. However, my gf had 3 bars on LTE and continued to browse the net. In order to get service, i had to turn on airplane mode then turn it back off. Later in the day when we were in the mall - my iPhone went to 4G. I figured this was normal given I was in a mall. However, I asked my GF to pull out her phone and she again had LTE! What's going on here? I want to take it to the apple store but I don't know how to reproduce the issue in front of them. They likely won't replace my iPhone unless I can reproduce it, right?