I agree. I got my ECE degree from Rutgers, which is considered by many professors to be the hardest at the school. I worked very hard but I always had time to relax with friends and unwind every day. I never pulled an all nighter and have never needed to, and feel it's a study habit smell if you do (barring extreme circumstances). I just learned to be efficient with my time, partition my work, and plan ahead. I considered relaxing as important as studying itself and programmed it into my routine. And you know what? I got excellent grades and had a great time.