Pros
Some great co-workers. Supportive management. Opportunities to learn new skills. Surprisingly good work-life balance given Amazon's typical reputation. I think this is very team and management dependent.
Cons
An insane amount of workplace politics. Some coworkers refuse to ever help you in any way. People routinely attack each other in group chats and meetings. Lots of passive aggressive behavior and competition between teams. Lack of commitment to projects. Projects constantly being cancelled on a whim. Annual OP review process for R&D projects creates tons of stress and uncertainty. Lots of pressure on departments without adequate support. Unreasonable expectations and demands for new products. Constant threat of layoffs makes for stressful and on-edge workplace. Also saw some good people PIP'ed for no reason other than workplace politics. Pretty toxic workplace.