Had my space grey 5S for a few weeks now, and the power button rattled out of the box. No issue during normal use, so I didn't let it bother me. But then I shot some video... A slight rattle translates to fairly loud clicks on recordings. I'm not shaking the phone, even the slightest movement causes it to happen. Have seen others online report the same thing. It renders recordings all but useless. It's definitely the power button, not the camera or vibration mechanism (it stops if I put my finger on the button), and happens whether in or out of a case. Had an online 'chat' with Apple support and they confirmed it wasn't normal and I should make a Genius appointment. I'm booked in for tomorrow, but wary I might be wasting my time, given the number of people elsewhere online saying it's an issue on many handsets. But aware that people are far quicker to report the bad than good, so thought I'd canvass opinion before embarking on an hour-long round trip.