Apologies if this is covered somewhere else in a thread. Has anyone else's 5s killed itself and needed to be plugged into iTunes to recover it? I was closing apps down and got a blue screen before the phone turned off and then displayed the iTunes screen. Quite concerned over this as I'm finding the 5s to be a bit pants compared to other iphones Ive owned. 3G signal terrible and it spends most of it's time on gprs where my old 4s was stable on 3G in the same location and call quality sounds bad to the recipient.