Avantages
Amazon is vary quality and customer focused. It is great to work for a company that truly cares. Most of the people are fantastic. They are very smart, and knowledgeable. On the other hand they are not stuck up like some people. You can get lots of work done without playing ego games. There is always something new and exciting to work with/on. For the most part resources are there when you need them.
Inconvénients
Although in some ways Amazon feels small. Some times your progress gets killed by big company policies and procedures. The management structure is very traditional, which is disappointing for such a progressive company. There is no way to get an independent review of any managerial actions, and the manager are given a lot of leeway. Because of this the flavor from one team to the next can be quite different. So you can't go by the way it is for your buddy, unless you are working on the same team.