[Milhouse]

Correct, not worth doing if you normally turn off the display. Its primary purpose is to save TV power consumption if you have a tendency to leave the display on while the Pi is not being used.

You could still use this script even if you normally turn off your display, as it will not do anything if it can detect when the display has been powered off, and will only kick in whenever you actually leave the display on. However not all displays will indicate if they are on or off, check if "tvservice --status" returns a different status when your display is on and then when powered off. If the status is the same then the script will not be able to detect when the display is off, and will always power off the HDMI (requiring an XBMC restart) even if you power off the display, in which case you'll have to decide if this script is useful for you or not (minor inconvenience and only a small power saving).

For those that leave their display on often, they should see a minor inconvenience (xbmc restart) but fairly significant power saving.