the new fitbit is a watch and has hrm built in, dont think its out yet as i cannot find it for sale anywhere
I think you are referring to the Fitbit Surge
This is a GPS "Smart Watch" as ooposed to the simple pedometer that is the case with the FitBit etc
One concern seems to be that the HRM is a light sensor. With thin profile bands like the ones on the new FitBit Charge HR and Fitbit Surge there is a risk of ambient light fitering around the strap to interfere with the accuracy