"it has been measured that it is more efficient to send your engineers home at a reasonable hour when a project is late than it is to have them work long hours. Efficiency doesn't scale with time spent, but exhaustion sure does."

Do you have any references for this? I worked for a company that was notorious for underbidding on contracts, which in turn caused an extremely stressful work environment where developers often put in longer hours, hoping to make up for "lost time". I personally witnessed people who were once brilliant developers write some of the most horrific code I ever laid my eyes upon (myself included). Although I know what you've said is true, I'd love to find a professional case study on the subject.

I realize this wasn't specifically the intent of your article, but I can really relate to that one particular part. ;)