I think it depends-- you can't have a job while in med school, whereas in law school, you can work full time and still be in class. The year and a half that I worked full time and was in class at night was extremely difficult. Also, studying for and taking the bar (while making trips at Target at night to pick up REDcards)
were some of the most difficult months of my life. With that being said, I really only had one difficult semester of law school when I had 4 finals, and the rest of school was pretty straightforward and not too crazy.