Vivosmart 4 Remarkable Step Counting--Check This Out

Bought VS4 to wear sometimes with Apple Watch or Regular Watches.  All my Garmins (F5XS, F6 Ti S, F6X S, First Avenger) have good step counting.  If I walk and count 100 steps I'll get 99-101, and not too many steps recorded with pure arm activities.  

Today I checked AW against the VS4 a couple times through the day. They were within 20 steps of each other.  So I decided to take a pic, and found them identical.  Have no idea if 100% accurate, but two devices recorded same # of steps from 6:00 am to 5:45 pm on this lazy day around the house.....  AW series 5 on left wrist, and VS4 on right: