Pros
Work life balance was terriffic at the Corporate office - it was very easy to put in 40 - 45 hours a week if you so choose, and often it was difficult to see the motivation to do more (see downsides). The travel benefit can't be beat, as long as you are in a city where you can get fly standby out. The people are great to work with, and the work is very interesting. Working for the airlines is something others are always interested in, which makes often makes converrsations outside of the office fun. You'll always know how to "work they system" on personal travel.
Cons
Career advancement seemed non-existant, and leadership didn't seem to have any plan to improve. After working for other organizations that show intense focus on the development of talent, it was painfully obvious American lacks the long-term vision to create new leaders within the Organization. This and the long-term propsects of the industry itself make it very difficult to dedicate 10-20 years to the company. Continuous concessions between management and frontline employees make things very difficult. In summary, this is a once great customer service company that no longer focuses on customer service due to the difficulties the industry as a whole has felt over the last decade.