No seriously, helps immensely when shooting, especially if the camera is something serious (and actually even especially) can, "save" a good 1-2 third Belichtunsstufen. There is also a security, whether in landscape photography or in the middle of May 1 riots in Berlin Kreuzberg. The camera combines formally with the photographer, you are not afraid that a good piece of gravity falls victim.
One can really say nothing more than: a must!