Hey folks, been using fitbit for over a year but I'm really considering swapping to an S4 since I've got an iPhone and Macbook and I'd love to have everything on the same ecosystem. Thing is, fitbit has one app that tracks everything and it does so very accurately. I realise I'll need to download some third party apps for sleep on S4 and see which works best for me but how accurate are the other readings like steps, calories, heart rate, work outs etc? Fitbit actually allows you to set the length of your stride each step to calculate steps walked and combined with height, weight and heart rate it estimates calories burned etc. What are these features like on the Apple watch? Is there much room for this kind of calibration like stride length? Are there any other features that would be better when compared to a fitbit? Lot of questions there I know, thanks a mil for the help folks!