Vantaggi
Everyone knows Amazon. After working there, when I talk to almost any employer, they are interested in me because I have Amazon on my resume. I had plenty of things to work on, so plenty to impress employers with during interviews. Things tend to move fast, which is refreshing to some who've worked in an environment they found too slow.
Svantaggi
Things move fast because management pushes people to get work done very quickly. This often comes at the cost of having free nights and (sometimes) weekends. Most managers don't have the capacity or interest in helping with their reports being overworked because they are also being overworked. Of course this also means the quality of what is being built isn't as high as it would be if built as a more manageable pace. People are definitely driven to prove they are better, smarter, and more capable than their peers. This often results in a lack of interest in helping each other and childish gossip. Management is trying to improve this through things like changing the annual review process to focus on personal individual strengths, but it will take a long time to actually change the existing culture.