Wow. Fascinating what different ideas of a 'great sleep' we have. I sleep almost every night for eight hours without waking, and consider anything less a 'bad night'...
I sleep about seven - and wake up 1-3 times a night. What I consider a 'bad night' is when I have a seizure as I sleep. Not as bad as having a seizure when half-asleep, or when having just awoken - but still.