Being a professor means answering students' emails up to 2 hours before your son is born, between contractions. I'm not kidding; that's when my last email from my advisor was dated, and she specifically mentioned contractions.
I do not get to slack off while my advisor's distracted; there's just too much stuff to do. The list of presentations and class work marches on uniterrupted, and there's no use pretending there won't be an end-of-semester checkup on the research. The real advantage is in the reduction of stress. I have the whole semester to get things done, rather than trying to meet certain checkpoints each week or every few weeks. Never underestimate the effect of being on your own timeline.