They do have a pretty bad turnover, many I know stay until vested then leave, a friend of mine gave his 2 weeks the day after he became vested.
I am not a fan of Amazon, if I needed a job I would work there to provide food for the family. They do pay well, we just lost a guy from where I work to Amazon, he went from a mid level sales to lower-mid sales at Amazon but his pay nearly doubled.
What I have seen is if you can survive amazon for several years there are many companies that will look favorably at your ability to put up with that environment.