Two major things: Set up as new phone and turned on music iTunes match to sync about 1000 songs over WiFi. Use cellular data was definitely switched off. Left the house and after about an hour or so felt my phone very hot in pocket and couldn't work out why. Shortly after I got an SMS from my mobile network saying I had almost used my entire months allowance. Checked and had used 675Mb of data that day. Seems iTunes match had continued downloading songs of cellular data! BEWARE! Auto-Brightess completely screwed. Does not adjust correctly and several times I have pulled out of my pocket to find an almost black screen. Slider 2/3 of the way up but brightness at it's lowest setting. This morning I woke and looked at time on phone and was complete opposite. Way too bright and slider all the way down.