I liked Bittorrent Sync and later Resilio Sync a lot, but they have been very unreliable when it comes to pricing and licensing, changing both several times.

Their license structure is currently worthless to me. I have a license, but that is only for home use. They only offer subscription licenses for business. Subscription licenses are harder to purchase in some organizations, plus everyone that I want to offer files to needs to buy a license as well. This is a large downgrade from e.g. Dropbox, where one can just hand out download links, open file submission requests, etc.