Since I first reported Numbersync was active yesterday, I had nothing but issues with it. After several "Light" resets and 2 Factory resets, countless calls back and forth with AT&T and one totally wasted call to Samsung Techs (Samsung if you're reading these threads, your tech support thoroughly SUCKS). Well I got Numbersync going on a couple of different occassions to where I have turned off and deactivated for the final conclusion.
1) Yes it seems like for the short time I was actually using it, battery killer.
2) At one time, I wasn't getting notifications such as text messages, i.e., that I should've gotten.
3) Got to the point to where my phone calls were going directly to my voice mail, couldn't receive a damn call, as AT&T Tech Support figured out.
4) In order to receive a call I would had to put the watch in Standalone mode, turning off the Bluetooth.
5) Then there was the couple of messages about the watch overheating and becoming sluggish. Never experienced messages like that until this last update with NumberSync.
6) NumberSync on the S2 would turn on and off by it's damn self, I couldn't even manually turn it on myself or off from the watch. Turned off via my account online and dactivated via watch to finalize it.
For now I'm leaving it alone until there is another update which will be needed soon, because of the glitches myself and others have noticed since getting it.