How peculiar.

While a full 8-9 hours of sleep does wonders for my constitution, I've found that I actually get considerably sharper with 5 or less hours in me... short term. It wears off, and I suffer later on.

Full sleep cycle, I struggle to get out of bed, and nothing short of a full-on panic-run to a bus will wake me up for morning classes. (This happens a lot because of point a, struggling to get out of bed)
Short-changed, I roll out of bed without so much as a blink, and I'm comfortably at the bus. Classes, I just blow through stuff like it's all second nature to me.

That said, my sleep cycle's about four to five hours out from where it should be; I start sleeping at 3-4am, and wake up 11am-12pm, and keeping such a brutal cycle of sleep as 3-6:45am practically killed me one time.