I like it, but I think it’s dangerous because of crazy car drivers. So if I do it, I stick to small residential roads.
My experience is the opposite. The hours 3-6 feel more dangerous to me because many drivers are in a rush and very uncourteous. At night there are just way less cars on the road and in general they are much more courteous. However I generally don’t ride light enough for them to suffer from very bad sleep deprivation.