I purchased mi band 2 a month before and I am writing this review after using it for a month
I have found some cons and prons
cons-
1.great batery backup(1 month)
2.light weight
3.easily charge
4 heart rate monitor
5.band vibrate after one hour if you sit blank for 1 hour
6.call and message notification(whats app, wechat, hike)
7.sleep monitor with great accuracy
8.easy to carry
9.it will unlock phone if it will connected with phone
10.pedometer with great accuracy
11.distance travel meter
12.great looks and ease in using by touch no need to know some technology of it
cons-
1.sometime heart rate mointor does not work yo have to set band in a particular location
2.calorie burn according to me is not correct
3.sleep time doesnot account afer 8 am to 9 pm .
but overall it is good fitness band in this range and its a great deal go for it