I worked 11p-7a at a residential treatment facility for emotionally and behaviorally challenged youth. The shift was given to me b/c I was a new hire and that was all they had, so I took it. Overall, it wasn't bad. The clients were all asleep, most the time, and it wasn't nearly as chaotic. The only tough part was the sleep. I never got too accustomed to it. Most mornings I would sleep around 4-5 hours, wake up and do some stuff, and then go back to bed for a "nap" before work.
After about 6 months I got transferred to the 3p-11p shift. I liked the shift better, but it was hectic from 3 until about 10. Hectic meaning fist fights, sexual predation, self harm, attacks on staff, etc.
So, night shift wasn't that bad overall.