Bittorent sync has been working great so far for me for 2-3 months until now. All I did was adding another computer running Debian to my setup. I realize since then that file has been synced 1-2 days late. I lost my progress on several assignments for schools. Luckily, they are stored in the .sync_archive folder. I turned bittorent sync off and use rsync manually for now. It is a pity because it is such a great product when it works.