biphasic sleep (I'd imagine that polyphasic is similar in this regard)
If you haven't tried a week polyphasic you have no basis at all for such a claim. Biphasic sleep is something with everyone can simply do, it takes no will power at all.
But over 90% of those who try polyphasic sleep don't have the will power for it.
1. From what i have read on the Yahoo Uberman Mailing list, those folk haven't seen real changes with exercise.
2. No 1,5 hrs + 1,5 hrs probably won't work.
3. The greatest problem is not that you are too tired to stay awake. The problem is that you are too tired to wake up and that your subconscious hijack you to turn the alarm clock off without leaving any memory of it.
Unless you find a way to drink the coffee while sleeping to wake you up I think it would be a real bad idea.
In addition coffee may reduce the amount of "sleep deprivation" you have. But you need the "sleep deprivation" to tell your body to adjust to the shedule.
4. Some of the succesful Polyphasic's are programmers, does that count as intellectual activities?
Since I'm already getting around 4hrs/night without any inconveniences, it doesn't seem to be worth it to go to polyphasic sleep to save just an extra hour a night (but I wish I could if I had a flexible schedule)
People like Steve have quited Polyphasic sleep because of the fact that it isn't a flexible shedule.
4 hrs without inconveniences is probably better than 2 1/2 with the fixed polyphasic cycle. But most people get problems when they subsedize sleep with coffein.