Its because its not volte enabled. Nor good battery backup.
And the camera quality is worst. But the display size is nice because its having 1080p hd display. This phone is very slow in charging, I mean slow charging take around 3-4 hrs min. Internal ram and rom are having very low capacity( 2gb ram , 16 gbrom-in use) . And as like before I am not able to get a fast support service au I used to get earlier.