Here is a link to the differences:
http
/www.tekrevue.com/tip/comparing-sleep-hibernation-and-hybrid-sleep-on-windows/
I use sleep (s3 in ram) instead of powering off. sleep/wake is a matter of 3 seconds because no ram contents need to be written to the hiberfile.
I normally do not care about ram contents and am not bothered if there is a power failure and I need to boot.