Oh, I spoke too soon after that last glowing review! Bittorrent Sync seems like a great new app, but I also discovered a huge flaw in how it works on my two machines. I just discovered that whenever text clippings are synced across my two machines on the LAN, they lose their contents. Somehow the syncing reversed and the original files on the first machine were also rendered blank. I had hundreds of these little files stored in my synced documents folders and in other places on the hard drives. Now they are blank. The files are there, but when you open them, there's no data inside.

After spending several hundred dollars for bulky complex and eventually not very useful apps, I accidentally discover BitTorrent Sync. Amazing...simply amazing. I had tested this program on my home network, and across North America while I am travelling.
Works like a charm. To make my statement even more solid, just let me mention that I have 125 sync folders with the total amount of data close for 4 Tb.
There is only one warning - sync large data by smaller parts - like folders or else.
Also, you can sync file aggregations such as DEVONthink, FileMaker or EndNote databases. BitTorrent preserves the package content, however, you must close your access to synchronizing files - allows to avoid conflicts in bidirectional syncing.

I would like also to praise the reference system of MacUpdate which made this discovery possible.

Had it installed 2 days now seems to do the job. Stable. Easy to use. Had liked to see an option to exclude some files.