Got my new F5 and am having a heck of a time getting it to properly sync and am selfishly hoping it not just my unit. :o I tried initiating the sync from the watch where it would continually show it was processing but the screen had text saying "searching for Wifi network" and when itinitiating it from my iPhone 5S I'd receive an error along the lines of "the unit is busy processing another actiivity".
Obviously I had a wifi connection, bluetooth enabled on the watch and phone, units were in close proximity, and no other tasks were running. It synced properly about 3 times and has errored out a >10 times. All other functionalities of the watch seem to be operating normally.