Very disappointed with accuracy of both Heart Rate and Steps. Walking on a treadmill set at 15min mile pace, the band only records a little over 3 miles walked at the end of the hour. Steps seem to also be about 20% below what my FitBit recorded. Heart rate is a good 23-40 points consistently below what the treadmill sensor reads and what I know my heart rate is about. I've tried with the Band reading from on top and bottom of wrist, same result. Sleeping function seems to be reasonable but I can't count on the resting heart rate as being accurate. Other functions for messaging, weather, etc. work well and for that reason I'm keeping but hope a SW update might fix these two functions.