What’s nice about Syncplicity is that it allows a single user the ability to sync Google Docs with files in a local directory. In addition, you can install a syncplicity agent on every machine you use. Sounds like Dropbox, eh? Well, Dropbox has better sharing features, but you can still share documents via Google Docs sharing feature.
So if you want Google Docs to be your main repository of files, esp. if your company has just migrated to the Google Apps cloud, then Syncplicity is for you. For the rest who don’t need synchronization with Google Docs, Dropbox still works great.