Doesn't always sync up with my phone. Don't know if this is the fault of the way he or my phone. I also had to buy a replacement strap as the one which came with it was causing a rash/irritation to my skin. I've never had this reaction to anything else and given how much I paid for the watch it's frustrating having had to spend additional money on a suitable strap. I've heard of others having the same issue so be prepared.
I bought this watch because I already had the scales from the same range so thought it would make sense to stick with the same brand but now I'm not so sure. You have to manually update with activities other than walking while there are other fitness watches which detect the activity for you.