Pros
In N Out is one of the few companies that honestly follows its philosophy. In other words, they don't just talk the talk but walk they walk the walk. I have never worked at a place where management actually cared about you (includes other restaurants and also professional jobs). In N Out is truly unique in this regard. If you work hard it will show and people will like you. I don't feel I have exceptional personal skills by any means. However, people generally seemed quite fair toward me (managers and higher ups). You are truly judged and promoted based upon an objective process/skills assessment. I would say politics were quite minimal although there was always some typical teenage drama. As long as you do your job and try hard, you will be respected and will move up the ladder. You won't realize how great the environment is until you leave for another job.
Cons
The typical cons of any restaurant. Sometimes work can be fast paced (possibly stressful for some people) although I actually enjoyed this type of environment as time went by fast. You also smell like burgers when you leave but what can you expect right? Cleaning the bathroom and/or other spills/weird events that happen can suck at times. Sometimes I had to stay later which could slightly interfere with school although it will negligible overall. I also disliked the sideburn/facial hair policy but its part of the company's image which they pride themselves on.