Well Mi products are always best budget products and their quality's for each product is premium here Mi Band 3 is best for their price, it have 0.78 inch OLED display wid pretty good brightness even in sunlight.
It's design is pretty good, but screen is curved rather than flat. Having a lots of features wid 110 mAh battery and a Heartbeat Monitor. Also contain Sleep tracking , alarm , timer and all activity tracking an many more features it have.Overall performance is very good, and Heartbeat tracker works as well. It aslo have NFC wid some models I am using it from many months.And it have special feature to reciev your call or search or phone from band. Build quality is too good conatin silicon strap.Overall I am satisfied from this product. It's really worth.