Another advantage of waking up early, if your employer allows it, is working four 10 hour days. I started doing that a couple years ago and would have a hard time going back. Those couple hours in the morning are golden because no one else is around. Having a three day weekend every week isn't bad either.
Four 10 hour days would be great, but I don't think I can concentrate for that period of time. As it is, my concentration diminished after about 6 hours of work.
The idea that I've found is better is the "Friday Meeting Day". Schedule all your meetings on Fridays and if the meetings progress quicker than expected give your employees the rest of the day off. It speeds up meetings (which is where employees tend to screw around) and ends up giving the staff an early weekend almost every week.