Pros
I get to work with a lot of really smart people on problems with scale and complexity that are hard to find almost anywhere else. I interview with other companies every other year or so, and they almost always are trying to solve a problem that a group at Amazon has either already solved, or is trying to solve at a larger scale, and who I can just go and join when I'm really interested in that problem.
Cons
You need to advocate for your own work/life balance. One of the impacts of Amazon's "Frugality" leadership principle is that there is always more work to do. The annual planning process, OP1, lets front-line teams and leadership prioritize what projects are important and what gets funded, but for most teams it's common to see more than half of potential projects not rise above the "funded" line, just because there is so much that can be done, including what other teams might want from you. So even when you're a rockstar and finish a project early and under budget, the next project is always ready to go. Beyond that, I often see new Amazonians ramping up into 50-60 hour weeks on their own. Sometimes this is because they think they need to prove something, but more often it's new college hires who don't yet know how to communicate delays or un-achievable dates. They're used to college courses with pre-validated and reasonable work, and usually still need to learn how to tell a manager that a project is underestimated or a new requirement will cause the date to slip. In order to achieve a happy work/life balance, you have to practice and get good at saying "no": no to your manager when asked if a date can be hit, and no to yourself when confronted with a project that you want to (or feel like you should) work on at the expense of your night or weekend. It can be done, and with enough practice it's easy, but you usually have to advocate for your work/life balance yourself.