Pros
Irrespective of team, department; all comes under one umbrella of Amazon's leadership principles. Those who can walk, talk, breath, practice and preach these principles at work can have a great career path. 1. You can explore any open source technology based on your area of interest (depends on how you manage and take time out from your project tasks) 2. You get to know large scale systems that supports Amazon. You are lucky if you get to build one of them.
Cons
A tech guy will forget and lose touch on many basic stuff due to availability of luxurious well built tools. (many amazonians question this point, but retrospect and you get to know the answer) You are taken for granted and expected to work anytime-anywhere. Manager holds the key of performance appraisal; there are many bad managers.