It all just gets out of the way.
I don't know why Gnome didn't adopt the Unity menu bar integration, instead you get to waste space on the taskbar on the bottom AND that useless status bar on the top.
1. You can set the launcher/taskbar/panel to auto-hide. 2. You can set up the screen corners (or a keyboard shortcut) to show an Exposé-style view of all running applications/windows. 3. You can have a global menu bar.
Are you referring to the Window List extension? Why not use Dash to Dock instead, or even Dash to Panel (not sure if it’s current state, I don’t use it) which will also replace the main top status panel.
I’m a GNOME user on a single display (X because NVIDIA and 3D industry apps) and it works well for me. I do like the other DE’s though, I’m pretty agnostic in that sense.
Most of the time when I think about Unity these days I think about the sidebar launcher and the maximized window mode integration, not the rest of the features it provided; I didn’t get to spend a lot of time in Ubuntu.