Unfortunately kids, wife, and job didn't cooperate with staying on polyphasic sleep.
I think the reason it keeps me more creative is that it's always morning. You are never more than 6 hours from waking up. And, when I've been awake for 6 hours, I start getting tired... take 15 minutes to relax... then take a 30 minute nap, and can get back to what I was doing with renewed vigor.
(I don't think it's the sleep deprivation that is the key part of polyphasic sleep. Polyphasic sleep with 8 hours of sleep a day - say, 4 two-hour naps - would still be polyphasic sleep. You do not have to be sleep deprived to sleep polyphasically. People assume that sleep deprivation comes with it, because when you sleep polyphasically, you need less sleep. Messed up cause and effect here.)