At the end of the day, in most workplaces, our efficiency and productivity levels tend to drop. Nothing unusual about this, we're only humans and we get tired. So, I think it's a bit strange that a 32-hour workweek (or 6-hour workday) still seems a bit controversial and odd.
Ryan Carson and his company Treehouse prove that you can grow your company, and at the same time cut down working hours. They have done this since 2006 with great results.