I made an experiment using Xiaomi Mi Band 1s and Mi Band 2 at the same hand simultaneously for a couple of days.
The general results are presented below. There You can also find the links to more specified conclusions as well as to the raw data I hope You will enjoy the reading and please feel free to ask questions as well as to add Your own comments and observations regarding two bands. I believe that will be helpful for the future Mi Band… users.
During the whole experiment Mi Band 1s always showed more steps than Mi Band 2. The duration of sleep measured by each band was quite similar. The main difference was connected to the deep and light sleep. Mi Band 2 has the tendency to show longer deep sleep. I made an experiment for six days and Mi Band 2 showed longer deep sleep four times.
The conclusion is quite simple: Mi Band 1s makes people walk a lot while Mi Band 2 users begin to sleep deeper
I did not check one-time measurement via Mi Fit app or with the help of the button on Mi Band 2.
Generally it can be told that heart rate data measured by each band continuously is quite similar. For people willing to use the band during workouts I have written the separate article on measuring high hr by MiBand 2.
I did not compare notifications. Thus, I would encourage people interested in them to use another source of information on it.
Of course, an obvious advantage of MiBand 2 is that it has a small monitor. You can check time and after the latest release the data, the amount of steps You made etc. on this monitor.
Please let me know about Your opinion on Xiaomi MiBand 1s and MiBand 2 in the comments below.