I think to summarize things I need to start listening to my body and doing my own programming. When I am working midnights I have to scale back my training and intensity of my training for two reasons. 1> My body isn't getting the sleep it likes to run on and 2> I am sleeping during the day with light beaming into my room (see Ben's comment on why this is bad).
I think there are universal laws that dictate a template that can be used to optimize training with diet, programing and sleep BUT everyone is biologically different and will run best at certain levels. Pat, for example, only gets 6.5 hours of sleep a night and still puts up impressive PR's. Although I could operate with that amount of sleep I do not think I could PR like that.
Just a side note, while I was in Afghanistan a good nights sleep was non existent. Every night was riddled with turret shifts or interrupted by the bad guys. Combine that with the stress of getting shot at and having shit blow up all the time, my body was definitely under high levels of stress. After 5 months I went on three weeks of leave in Italy and Greece with my girlfriend and mom. I was a freaking zombie....I hardly remember major events that my mom and girlfriend can easily recall. All my body wanted to do was sleep.
I need to geek out more on the effects of cortisol (stress), on the body. Long story short, I think that everyone needs to minimize artificial stressors and stop inducing a large cortisol response from irrelevant stuff such as, driving to work or too much cream in their coffee.
For myself, I think if I want to hit PR's I should get more sleep and program ME days and longer time domain MetCon's for my days off. Now an insightful quote from Pat...