When you open the overview panel, it cover's part of the content and makes it unreadable. It is getting even worse when you open the separated panel UIO (Click the button "Show Display Preferences"). Possibly it could be fixed to open like the top panel (It slides from top and pushing the content down), it could slide from left and push the content right. I think with this improvement the page will get more readable, and will look better.
Also, even when the overview panel is closed, and UIO is open, it's icon is covering a small part of the top panel. I think that should be fixed too.