[microtonal]

but now there are a million options that are probably just as good

Few of them have block-level sync or LAN sync. In practice, Dropbox is often much faster than alternatives, especially when syncing/modifying large files.

The only programs that are better at it are Bittorrent Sync and SyncThing. And they are specifically made for peer to peer syncing.

[geoelectric]

Yeah, I was sold on Dropbox the first time I stood up a machine and it synced a couple of GB in a few minutes. After scratching my head because my broadband isn't that fast, I realized it had quietly sideloaded the data from my other signed-in box on the network. That was pretty spiffy.