Mi Band HrX edition is the successor of Mi Band. The difference or the feauture which is missing in HRX edition is the Heart rate sensor. Other than this the data shown by band is almost accurate. Battery back up for the band is fine. I used it personally and bery easily battery runs for almost 10 days in a full charge. Build is fine. The strap which they provide in the box. needs to be improve. Pairing process is also good. The only feature which lacks is the heart rate sensor. Anyways that is not a concern for most of the people.