A:Answer A : the Moto Z line is medium grade which means they don't perform as well as SAMSUNG performance smartphones. Therefore, the 5G MOD is unique to a medium grade platform but the battery pack MOD makes it competitive with twice the battery power than any other smartphone. The Z3 is an excellent screen with a nice fingerprint sensor on the side; Z4 has an on-screen fingerprint sensor with a slightly larger screen. Both devices have CPU processing speed issues that might become problematic with 5G data speeds ( oh, don't forget the UV radiation levels! ), That's why the 5G smartphones are $1,500.