Avantages
Many talented managers and employees. Management was generally aware of problems with technology, departmental communication, etc and worked to fix them (slowly but surely). Regular reviews of employees. Good bens (health insurance includes massage, physical therapy, mental, etc and dental is inexpensive).
Inconvénients
There are a lot of dead end jobs at Amazon. Although, it seems like the potential for great career growth should be high there given the size and breadth of the company, many good employees find themselves trapped in boring, tedious jobs for way to long with no potential for recognition or advancement. Thus, it could be necessary to work at Amazon for a couple years to get that line on your resume, then go elsewhere for upward mobility, then come back later when you're qualified for a higher level position.