Hibernate or Shut Down---> Which is better???

[Tyrol]

I usually let my computer go into hibernate mode whenever
I leave the house. But sometimes, not always, it may take
just as long to recover from hibernate as it does to start
the system, I guess depending on how many files from
memory have to be re-loaded. I am wondering is it better
to shut down your system if not in use for more than two
hours or is it better just to leave it on and use
hibernate? I had heard that starting and re-starting the
hard drives can wear them out. But the same action occurs
in hibernate mode.

TIA

Tyrol