because synching runs all the time. any change that I make is nearly immediately updated offsite. and if you think that is my only backup of my photos, you would be wrong :-) This is only a “if I lost all my physical possessions” type backup, not an “oops, I am a dummy and deleted something I shouldn’t have” backup. I have multiple snapshot backups and also run incremental backups every hour. Storage is so cheap any more that I don’t hesitate to have 5 backups of the REALLY important stuff. Most of my server storage is also raid5 in case of hardware failure. I have pushover set up to check for disk failures and push alerts to my phone if one is ever detected.

I have a site to site VPN between my house and my mother’s house. I keep a raspberry pi at her house with a 2TB drive running syncthing. My photo library and important documents sync to her house as an offsite backup in case my house ever burned to the ground.

as far as syncing files between PC and laptop, I would think ownCloud would be better suited for that.