c7 have larger screen plus internal memory and fm transmitter
but i forget it is clear balck display or not ><

BTW no recommended 1st bath c6-01 cause some got black call screen problem and mine one lay at hospital waiting change lcd due to purple color at lcd

try insert sin card and make call and receive see got display or not. Than open white picture or snap it with the camera. To check for any purple color issue or not. If no have above sign than just do other simple checking and testing.

Bear in mine the purple color start small and grow larger in time. So check carefully