In last week's Google App updates, Google announced that the PC/Mac Drive sync client now features more granular control over folder syncing. Rather than simply choosing which root folders they want to sync, Google Drive users can now specify exactly what they want at the sub-folder level.
To try the new feature, open the sync client Preferences and choose Sync Options. Here's a handy gif Google provided to demonstrate the new feature:
The other updates announced last week included better visibility into storage usage and better warnings for when users move or delete files or folders that have been shared with other users. These are useful, but I think most users will be more interested in the sub-folder syncing.