I agree that burnout is a serious issue and relaxation is of the utmost importance. That said, I've hit and many times surpassed the 80-hour work week for week

I agree that burnout is a serious issue and relaxation is of the utmost importance. That said, I've hit and many times surpassed the 80-hour work week for weekly - and occasionally monthly stretches - plenty of times in my past 10+ years as a developer. I don't recommend it to others, but I do enjoy it and the fruits thereof (creative, moreso than monetary). I also maintain an active social life and a healthy long-term relationship. Both of which are born of a solid understanding of my strange schedule from those close to me. I also work from home 90% of the time, which makes it far more manageable. I wouldn't want to attempt my schedule with a commute involved, but I don't doubt it's possible for others.