I just added sync to two devices running FF=31.0 I got the confirmation email, signed in, clicked on Manage on both browsers. But now what? After an hour, nothing has changed on either device. Am I supposed to find a StartSync button? There are lots of questions about a progress or status for sync but no resolution. The about: sync suggestions mostly do nothing or don't work. Do I have to restart Friefox on each device?

There doesn't seem to be any information about differences between two devices, ie, how are duplicates handled, or will new items and tabs be merged between the two devices?