It is highly recommended that you always shutdown your computer after saving your work and never push the power button all the time, it messes the operating system and might just get the complete System non working. However there are situations where you just want a shutdown which doesn’t ask you save anything, more like unattended shutdown. The only advantage I see is you need not to wait for everything to close and see the shutting down windows.
Instant Shutdown is just built to do this. This application can shutdown your computer like you pulled of the plug as it does not ask you for saving any files which are in use or unsaved, so if you use it will be lost. However it’s not also an adruptive shutdown. It takes care of proper shutdown but doesn’t ask you for any open files etc which saves a good amount of time if and only if you are in hurry
In case you are looking forward to programs which smartly shutdown, you can try Shutter or Shutdown Manager which is pretty advanced with a web interface or dead simple program like Auto Shutdown which is like a shutdown timer for your windows. In case you would like to abort any of the ongoing shutdown, you can use shutdown -a or shutdown locker. More ShutDown Tools here