Japanese Sleeping Hours

I can tell a tale or two (and I have in the past) about Japanese working hours. The majority of Japanese seem to spend most of their life at work. A typical day is a 10AM start and a midnight finish. I remember back at Amazon people sleeping in the office too.
According to a recent survey however, it looks like the Japanese are working even more and sleeping much less.

I'm usually up at an average of 6AM and try to turn in at midnight. Any less than 6 hours sleep means that I get sleepy after lunch. Sometimes I would get into the habit of sleeping even less but usually ends up with me getting sick.

Whenever possible, I try to make time at night to tidy up my mind a little by going over what I did that day and plan for the next day. By doing that while I'm awake, I find that I sleep better and am guessing that it helps take some burden off the brain from processing these thoughts while I'm asleep? Have no idea but it seems to work.

A friend of mine was saying that through his studies, humans should be able to get by with only 4 hours worth of sleep.
I've also heard some people say that people who sleep less die at an early age. I find this statement interesting and wonder occasionally if the time allocated to us by fate is predetermined.

How many hours of sleep do you get on average? Do you try to sleep less to get more done? If you knew that sleeping less (and getting more done while you are young) meant dying at an early age (lets say at 55 years), would you sacrifice sleeping hours?

For those who find it a bit tough to wake up in the morning - you'll need one of these. Once you have it, you wont need an alarm clock to get you out of bed. Its what drives me every day.

BTW, the adorable sleeping girl is Nanaka-chan from DC2.