I am experiencing wide variations in step counts at the same settings. At the default setting it is ranging from 5% to as much as 20% over the actual step count. This may get better as I adjust sensitivity, however, some additional comments. The milage appears to be calculated by step count. Assuming this is the case, you need to be able to input stride length in order to calcuate acurate milage & speed, even assuming you can get the step count correct. I make these assumption based on my observations walking the same route. That is, if I get a higher step count, I get higher milage for the same route (so it is not, apparently using GPS). That said, the numbers in the picture above fly in the face of this assumption. To get 1.42 mile in 1600 odd steps, as in the illustration, you'd need almost a 60" stride. That in itself, is a pretty poor illustration of likely accuracy. In reality, I have found the milage to be more accurate than the step count, therefore probably calibrated a bit low for my stride. In addition, somewhere, if only on the support site, it would be nice to see an indication of which direction to adjust the slider to increase/decrease sensitivity. I realize that this can be figured out by rote, but for the sake of completeness....