The oneplus z is same as oneplus one but thw difference is the bild quality and the screen size the oneplus one screen size is 5.5inch oneplus x screen size is 5inch
Biltquality and looks
The looks of the oneplus x very good ita look premium in hand and it all made up glass and metal it looka very good
Performance
It performance is also very good it powered bi snapdragon 801chipset with 3gb of ram
Screen
It has 5inch fullhd acreen it looks very good
Battery
Battry is one week point in the mobile it has 2400mah battery that will get u through the day