Vantaggi
Able to maintain a healthy work/life balance. Fun, friendly work environment. Interesting projects. Amazon is a very challenging workplace. You're expected to get things done very well and very quickly. There are a vast variety of projects, big and small, to work on to stretch your skills. You're not just interacting with other software developers, so you can use it as an opportunity to learn a lot about business in general and people skills.
Svantaggi
Despite the long-term vision of the company executives, it seems that a lot of the lower-level managers have very short-term vision. They will cast your best laid plans asunder in favor of rushing out a completely new project in a very limited timespan so they have something to show in their regular meetings with top executives. As an SDE, you have to learn how to push back and get time to make a solid plan. Your developer as a programmer may be limited in terms of the developer tools you learn (and can use to pad your resume). Amazon uses a lot of proprietary developer tools. The on-call rotation is very frustrating and exhausting at times, but it's a necessary evil. It has driven people out of the company. But the severity of it is something that varies greatly from team to team.