I've been using https://pydio.com for the last 6~8 months, and so far so good. I came over from owncloud. Admittedly, I had planned to use for my family of 3, but I'm really the only one using/syncing stuff. THe server side for pydio has been great, though their Windows client has had a few little issues. In all cases they were easy to fix, and ultimately caused no damage to server data (who knows it could even be a local Win/laptop issue). Though pydio is php-based, while seafile IIRC is python (I like both languages so doesn't matteer to me, but thought you might want to know ahead of time).