I m using mi band from 5-6 months.
Its really good low budget smart band. mi band track your footsteps. its also calcute our sleep time, how many hours you are in deep sleep and how many hours you are in light sleep. Battery backup is very good, band gives 30-35 days battery backup after full charge , It will not take so much for charge. Its also have security system. Some interesting part like connect your friend and challenge them.
And many more having this band.
Thank you.