While using tabbed docks would do the job, ObjectDock (to me) doesn't hide as conveniently and is a little more clumsy... as in its takes time to go off screen when auto-hide is set, whereas Fences disappears/reappears instantly with a doudle click and has a smoother transition.

I have ObjectDock Plus, and while it has more feature/options, I've found myself using Fences more and more because it is so simple and convenient.... though the ability to add tabs would be a welcome feature, should it ever be added.