I purchased a new iP6 on 10/31/14. I had an upgrade I was happy to use as I was still on my old 5. First thing I noticed was people saying they could not hear me on the phone, then wifi spots would be extremely slow and websites would time out before opening yet my old ipad would spring them open. Lots of calls to apple and wiping and re setting up let to me getting another New phone 2 weeks later. That phone had its own issues plus some others. WiFi was fixed but the call quality remained poor and the phone would fail to illuminate. After a call ended, I would go to hand up but the display remained black (unlit). this happened 20% of the time. I could still talk to the person but the screen was black. Eventually the phone would either need a reboot or sometimes came back to life. After weeks of calling, re-setting and frustration I visited an apple store in Florida while on vacation. There they hooked my phone up to a diagnostic and read 24 memory errors, 7 hanging app reports (apps that I am not in control of) and various hardware errors. I was sent another new iPhone and we set this up without using the icloud back up which the apple tech though might be corrupting the software can causing the hardware to run qwirky. I received the new phone Friday 1/2/15. Called Apple support and they talking me through backing up what I needed usoing iTunes, icloud. All photos were moved into the new camera roll via air drop. I deleted all old icloud back ups and re set up exchange. Loaded everything onto the new phone and so far so good. I did a new back up and I believe I am all set. Will keep you posted. It seems that the icloud back up was the issue and I came to let anyone have similar issues that this could be the issue.