Had the Mi Band 3 for over a year now. Bought in Jan 2019 to track my steps and length of time and heart rate when I exercise at gym.
PRO's Battery Life is great - last weeks almost a month Shower with it, swim in the surf with it - No issues. Tracks steps no problem - AND it syncs with Apple Health no problem. (and therefore Pokemon) I have found the Heart rate is accurate when exercising. Receive SMS no issue. Oh.... and it is a watch
CON's The app on your iPhone is not intuitive, while it tracks your steps, weight, heart rate during exercise, etc. to get to all this information is not intuitive.... BUT it is there.
Wrist Band loop broke after a year. Bought 4 new wrist bands on Amazon for about $15.
I would happily recommend the Mi Band 3.......It is not flash or sexy, but it does work and does what is says it will do.