Hmm. If I have more than 4 hours of sleep, I tend to last the day at a near average level of competence with a shot of caffeine. If I don't get 4 hours of sleep, I either call in sick or If I only have a single lecture or the like, brute force myself through it and rush back to the bed.
Having said that, during the work/academic year. My sleep pattern tends to be VERY regulated that basically ensures me getting between seven to eight hours of sleep a night. While I can jump the gun on a few days a month, it's hardly what I wish to do. Stuff just happens more nicely or I get over some annoying shit just so much easier when I'm rested.
Moreover, I don't really do intensive stuff after a hard days of work. If I do watch anime before going to bed, it's going to be something like Aria or Hidamari sketch, or dragon ball. Something that I can just turn off and enjoy. Most of the stuff I do either professionally or as a hobby requires a fair amount of constant concentration and my brain just overloads. That's about why I avoid artsy films and the like like the plague.
Hmm, my body doesn't go to sleep if I lie on my back, during the last few years, if I wanted to force myself to stay awake all I had to do was lie on my back. However, I never forced it to the extremes you lot do, 70 hours? Fuck that. I can't remember ever going past 50.