I'm an RA, and at my school they tell us to plan for a twenty hour work week. Truthfully, there have only been a few weeks this semester with that much work. Most of my job is planning programs, dealing with roommate conflicts, helping out students and attending meetings. Also, I have duty two to three times a semester, which requires me to stay on campus for the night and walk by all of the rooms in our area either before or after quiet hours, to make sure that nothing crazy is going on.
Personally, I love it. Not only do you get a private room with free room and board, but you get to make great relationships with the students in your hall. It can be incredibly rewarding. The first in first out thing is very true. We move in two weeks before everyone else, and I remember sitting in my room before winter break, waiting for 5pm to come so I could leave
If you have any other questions about it, you could pm me!