What is that 'minimal windows manager' and what is the benefit of it over Unity (which to me is a few icons down the left and a few icons + notifications in the top right)?
The big advantage of tiling vms is that you always use the whole screen area without having to only use maximized windows. You can easily split the screen into several areas where you can put windows. Another advantage is that they are usually keyboard driven so that it is possible to launch, close and arrange windows without using the mouse.
The one I like best is wmii, which has a brilliant column system combined with tags instead of workspaces(i. e. a window can have several tags instead of only one workspace). Nowadays I use i3 since it is a bit more modern but so far I find that the usability is not quite as good.
It's strictly possible to do this in most non-tiling window managers. The key difference is that arranging windows with the keyboard is not just possible but significantly more practical.
Speaking for Openbox (since it is what I use) the benefits are numerous: less lost space on screen (UI is customizable to the pixel simply by editing an XML file); extensive and customizable keyboard controls (again, just by editing a simple XML file) for managing windows (resizing, positioning, etc.) but also for launching applications and managing multimedia keys for instance; more lightweight in term of resources (not that important, but always nice); and being compliant with ICCCM and EWMH standards which allows extensive external scripting using tools like wmctrl.
What is the benefit of Unity for someone like me?