FitBit or Nike FuelBand?

I bought a FuelBand when they first came out and was really disappointed. It doesn't accurately measure calories burned, instead they made up their own measurement called "fuel" that it somehow calculates based on your movement. It does give you a number for calories burned but it is very low and not accurate. Also, because it uses an accelerometer...it only works for activities like walking or running where you are taking steps. I am interested in learning more about the FitBit.