Avantages
Really smart, motivated employees. You ship software often and can see the results of your work frequently. One year at AMZN is equivalent to several years of experience at most other companies. If you look around you can find really cool projects, many of which are greenfield and do not require supporting old code. Having Amazon on your resume will also open a bunch of doors for you. I received a never-ending stream of emails and phone calls from recruiters while I worked there. Generally speaking, you have a great deal of latitude in working on things that interest you.
Inconvénients
Jeff Bezos is never going to retire. This means that VPs and above who are at Amazon are fully aware that they will never be CEO. It can be argued that this reduces the pool of talented leaders who are willing to work at Amazon. In my experience, the executives at Amazon tend to be less competent than at most other companies of similar size. Also, although they will claim otherwise, it's an intensely political environment. Many directors, VPs, etc can fail over an dover because they have been there forever. Carrying a pager is either neutral or a big negative. If your team has its stuff together it's minimally invasive. OTOH, if you're supporting crap pager duty can be hell.