Pros
You get to learn a whole lot of neat technology at Amazon. It is a very vibrant place and generally the people you work with are friendly. They do compensate you well but there is a reason for that as the explained in the 'Cons' section...
Cons
On-call duties are the worst--very high pressure in which you have to try to solve emergency situation often on code you have NEVER seen before (someone else's code in which that 'someone else' has probably left the company long time ago). Also, getting help from others can be tough at times since everybody is quite busy so you have to find the solution on your own via the company Wiki, etc. Also important is culture: Amazon has lots of 'young' folks and you can sense the condescension from them to older folks. In fact, quite a few of them seem very cynical when interacting with the older generation.