Mi 3 was one of the best designed smartphones at that time with smooth and yet sharp curvy edges. Even the OS was refreshing as its interface was different but simple. It also has a better battery life and usually lasted a full day.
Camera was great. Clicked some amazing pics with that. It was definitely a good value for money.
However, the only drawback was its non expandable storage of 16GB which wasn’t sufficient. An expandable storage option would have made the phone even more successful.