I tried the charge3 and the step and stairs-climbed counters both read wildly incorrectly. It also had a tendency to track steps taken when driving. They also hadn't got the pulse-ox sensor doing anything at the time I returned it.

The OS on it is quite nice, the iOS app isn't bad either, but the inaccuracy just drove me nuts.

I moved on to a Garmin vivosmart instead. Not quite as pretty, but a lot more accurate.