Pros
Amazon is stoked with bright people, a reasonably fast pace, ever growing and expanding business, and a vibrant startup culture. Over the years, a lot of rough edges have been smoothed, and if you're on the right team (there are many great teams), it is a great career experience. The fact that Amazon obsesses over customers tends to filter out the ego maniac managers and rude people (if they can get hired by Amazon on other merits). Over time, those folks don't survive, because they end up doing things that negatively impact customers. Amazon has added extra opportunities for guest lecturers on a variety of deep technical and scientific topics.
Kontras
Sometimes, obsessing over customers can be a compulsive behavior that means the company is overlooking the wellbeing of the "owners" (Amazon-speak for employees). Lately, though, some public light has been shining on a few cases where employees weren't treated well, and that has resulted in some additional care and attention internally. I don't personally know anyone with a negative story like the ones in the press that concerned me. There isn't a lot of formal training around career growth. Technical Program Managers (TPMs) are a less populated group at Amazon. It's a bit harder to learn from peers as TPMs tend to be embedded in another team. The benefit of working embedded is that you can feel a sense of continuity, ownership, and deeper knowledge. Unfortunately, the alternative (working in an org of TPMs) seems worse as you may be jumping in and out of multiple products and projects and can take the heat for any one of them that runs into problems (I've heard stories of TPMs in this org style going up in flames)