I've done the course a few times now, and I would say the hardest part is integrating meditation into daily life. Goenka recommends meditating twice a day, one hour each sitting. Sometimes this isn't possible, so I just try to meditate however much I can.

I have heard from others that serving a ten day course (as opposed to sitting a course, as the author here did) is more beneficial as you are able to talk with fellow servers, help prepare food, and can even read a newspaper. Although you can't go deeper into your mind, you learn to integrate meditation into daily life better. I have yet to serve a course.