The mi4 is the great smartphone from xiaomi it has good Features. The miui rom in the device does good work with us and it highly customizable
The camera of mi4 doing great job, it is 13 megapixel, the phone does not hang and flawless working.
Camera pictures good in daylight but not good as in low light. It has 3gb of ram for multi tasking.
The design of the smartphone is great and its look very nice, The display is easily visible in sun light and its very sharp display, it has full hd resolution.
The device also support otg so it is very helpful for all users.
Some time device warm up in heavy uses or in gaming, calling, charging.
Battery performance good it is 6-7 hours in wifi uses. Phone does not have external sd card slot so it is cons.
The phone support all latest hd games with out any lag, it has different sensor proximity, accelerometer, compass, gyroscope and other working great. I like its miui updates it also gives much more Features in every update. Also the xiaomi plans to update it in Android marshmello 6.0. Finally it is great device works very smoothly.