Pros
Best reasons? it's a challenging environment with many diverse routes to take in your career assuming you perform well at each stage. People are held accountable for the most part (exceptions everywhere in life). The bar is high which makes for teams that do strive to operate at a level that other companies give up on.
Cons
Careers are made or broken based on the team you join. do your research. And once your in, listen to your instincts. if you feel that you are performing at a mediocre level (and we all know when we are) - chances are it's not un-noticed. If you are struggling to fit in, chances are it's not a fit. If you had anxiety, depression, insecurity before joining Amazon (or any company), no one can fix that but you. If you find yourself too stretched, get a mentor, regroup, take a step back. self-awareness is a blessing and a curse, but essential here.