I am with yall on the 7+ hours thing. Especially during healing times like right now, I feel excellent with around 9 hours of sleep. I just go to bed pretty early, around 9 and wake up between 5 and 6. Generally if I am awake during the hours of 11pm-5am I am one unhappy, sensitive individual, and it does affect my mental and physical acuity the next day.
There are times during the summer, when I am feeling really excellent and working outdoors, when I have taken naps around 2pm-4am and then wake up between 6pm and 8am and get back to work or life and then fall asleep around 11pm and wake up again from 5am-6am. But that's pretty rare and really only during the longest and hottest days of summer. That really has to do more with the heat and sun and never happens in the winter. During the darker colder times of the year I am up and outside as long as the sun is up and tend to be outside in dark mornings and evenings a lot if its not too cold but always sleep through the night. I also sleep more hours in the winter in general, especially depending on how far north I am living.
I don't know, I think it's all cyclical, having to do with the seasons, where you live and overall health. Sleep is so important for health and healing, its one of my most cherished times:)