Oh dear god...it works without a bumper...just some people who HAPPEN to live or work in low signal areas get the dreaded no signal...the phone works as it should and with the recent updates the signal issue isnt such a big problem anymore.
debatable . i never had calls hanging on my old phones . i live at the same adress and am on the same network

its only happened a couple of times though and i only bought it after knowing we where getting a signal booster soon. its the fluctuation of signal that i find weird. constantly moving from full to none , whereas my old phones just stayed at 2 or so bard constantly