Just to be sure, I tested this. I set up inotifywait on a BitTorrent Sync directory, then moved a file in. inotifywait returned immediately, while it took 10 seconds for Btsync to start the sync. I know this is expected behavior from this post. I have worked on file sync programs before, and this is typical. This is a settling time to allow disk activity to halt before beginning sync. My use case is a bit extreme as far as what I am expecting the program to do, but so far the only hold-up is the 10 second wait.