If all you're doing is working and sleeping, you're neither making good decisions nor thinking hard. You're just faking it and making up for your burnout by getting less done.

That extra long hours speed the time to market is an illusion. It doesn't work. In the vast majority of projects, burnout hours are a direct result of a failure you can't admit to.

I'm not saying this only because I don't like sweatshops, it's because I have yet to see quality code from a sweatshop. When I've worked in sweatshops, I've found that the most productive people were never the ones working the longest hours; on the contrary, those of us who were smart enough to do our jobs and go home and get some rest ended up picking up the pieces from the all-night crew every morning.