Hibernate instead of Shutdown for faster performance

When you boot your computer, certain critical modules (like kernel) are loaded into the Primary Memory (RAM) which allow the operating system to start. After this whenever you start an application (like Microsoft Word or Outlook) it first gets loaded into the Primary Memory from where the OS loads the Application. Thus, the first time you start an application there might be a delay of a few seconds and the next time it'll be much faster.

Hibernate saves the contents of the RAM into Secondary Memory (Hard Disk) and when you boot the OS next time, it simply loads the RAM image back from the Hard Disk.

Thus, even though time taken for a normal boot vs time for a boot after hibernate may be similar, you save a lot of time while working on the same set of applications.