Avantages
People are really dedicated to their work. Amazon does not have a culture where you are told what to do, you drive the work, you are argue on the prioritization, change the way your team operates and impact the delivery. You work with extremely dedicated and sincere people, who work as if its their own company. You get to learn end to end on the development from requirements, development, testing, deployment and maintenance.
Inconvénients
If work is not your first priority, you may feel that work is encroaching in your life as you hardly get time to practice your hobbies, etc. No one asks you to work over time, but because of peer pressure and how things move, you may feel the pressure of being available to your clients after office hours. If you stop working as a learning experience, things may not look very much on schedule.