Syncthing

Advantages

• much faster than Nextcloud, once it gets going.

Disadvantages

• no way to access files in a share without downloading all of its files
• no central server (even as an option) for easy access when outside of the LAN

Needed Features

• import/export for the shares on any given system
• a "notes" field for each share, so you can document its purpose/usage
  • Ideally, there would be both public notes (which would be shared along with the files) and private notes (which wouldn't, and could be added to shares defined elsewhere).
• a way to include linked folders in the sync-set/share
• ability to connect to specific folders within a share, and attach them to whichever local folders I want
• ability to browse available shares without downloading them or setting them up
  • (This would also make it possible/easier to start setting up a synk without having to wait for the invitation to arrive.)
  • ability to download/upload specific files without synking
• notification when local disk is full
• when a remote or share is "offline", some kind of explanation of why -- seems to be multiple possible reasons (including local disk full, which shouldn't be)