Pros
Best American carrier for quite some time now. Lots of schedule flexibility. You don't have to live I base if you plan waaaaaay ahead, but it's possible. Free flights around the world and plenty of opportunity to go places paid on Special Assignment. Best uniforms among US carriers. Practically the only way to live out your life's travel fantasies as a normal person in the United States unless you are apoplectically wealthy.
Cons
No union protection for flight attendants which allows inept, inexperienced managers of flight attendants to act reactively and often punitively without any recourse or transparent review process. Seniority means way too much, especially considering crew won't retire but rather fly until they die, often with 40+ years of service! with some crew either embarrassingly overweight, lazy, poorly groomed and damaging to the brand compared to international competitor crew. Crew regularly are turning 70 years old and continue to hog the best trips or sell them to juniors. Terrible salary for first 5 years. Backstabbing employees write you up in an attempt to get ahead with management. Scheduling makes up the rules as they go along.