I don't believe you are an 80 hour a week man. Unless you count reading HN, browsing the web, reading email, eating lunch, commuting to work, getting ready for work etc. NO ONE does 80 hours of legitimate work a week. It's a myth.
There are 168 hours a week. Say you sleep for 8 hours per day. That takes up 56 hours, leaving 112 hours. If you legitimately work for 80 hours, that leaves 32 hours of downtime a week, or roughly 4.5 hours per day. That's only 270 minutes (it's closer to 4.6 hours, but that is only 276 minutes).
270 minutes a day. What can you accomplish in that time? Is there enough left over to stay sane?
Of course, there are plenty of variables to play around with. Sleep 6, and that's an extra 14 hours a week. Now you have plenty of downtime. Over the long run, is stealing these two hours away from your sleep beneficial? Maybe for some. Are you in that category. Are you sure? Really?