So my 4S is doing some really weird things - sometimes decides there's so signal when there clearly is, calls don't come through (I just get a voicemail), randomly reboots itself and the phone will often die when the battery is at as much as 35%. So I need a new phone. It appears I have 2 options: 1. Sell the 4S and buy a 5S. But the 5S is 9 months old and still at full price. In a few months the 6 will come out and I'll have an almost new but suddenly old 5S. 2. Hold out and hope I can cope with the 4S until the 6 comes out at which point my 4S will drop significantly in second-hand value. Plus, there's a chance my 4S will die altogether before the 6 comes out. Unless there's another option I'm missing?