Sync the most current files first! Why would we want to wait for old archive files to sync? Many of us are travelers and work at multiple locations.
Users are looking for a unified desktop, when collaborating on limited bandwidth we need our current work to synchronize immediately to be efficient. Often a user must stay in a high bandwidth wifi until files sync.
Also if any error deal with them last. Why would a user have to see that a error held up completion of other files. These is frequent when using Windows Explorer and copying a volume.