How are you finding BTSyc performance? I was a big fan of the alpha, but it would choke my Pi v1 every time it indexed. I found it quite useless for large folders.
There is another sync option I am evaluating on my PC - SyncThing. Haven’t got around to installing it on OSMC (it’s just an executable). It has big advantages over BTSync - open source and more secure - but I have a feeling that it will also bring Pi to it’s knees when indexing large directories.
In the meantime I just learned how to use Rsync and it does everything I need. Currently I’m syncing an 80gb music folder to a backup server - the performance is outstanding, low memory with no cpu spikes. All nice and stable. YMMV…