I ran the two devices side by side for a few days. Thanks to Eric Jain and Zenobase for the hourly data! Love it!!! I used it to create this graph in JMP. Although I have used the FIT for 4 1/2 years, it was a remarkably easy switch. I had planned to wear them both for longer but between the heart rate monitoring and wrist wear factor and weather getting nicer, I haven't put my armband on since. Although the step counts aren't exactly the same (Fitbit seems to be quicker at counting non-exercise steps), close enough. The calorie burn is remarkably similar device to device.