I prefer to disable the scene tabs for maximum workspace. I often don’t need them and manage my scenes differently.
There is a minor bug, at least in win7x64. When saving a file with the scene tabs disabled, they will be visible again at the next time you do a fresh start(!) of SketchUp. In the menu though, the scene tabs are not enabled so you have to go twice to menu -> scene tabs to actually disable them again.
See image: freshly started SketchUp, opened a file where scene tabs were not enabled but still visible in screen.