It's a WebDAV server, so it's more like FTP than Syncthing.

Syncthing (as the name implies) is meant to synchronize folders across machines. QuickDAV is meant to transfer files/folders from one machine to another. They definitely both have there uses, and there uses might overlap in a lot of cases, but they also have there own niches. Like, I wouldn’t use Syncthing to transfer a photo to my desktop once, and I wouldn’t use QuickDAV to keep my photos directory synchronized across several machines.