Pros
Most people are smart, friendly, and happy. The pay is amazing and promotions are part of everyone's career. Get to work on top of the most wide-reaching technology and have the backing of such a large company.
Cons
If you let them, managers will devour your entire life and get rewarded for it. Not everyone, but enough people play dirty office-politics to make some departments fester and become downright poisonous. The "away-team" model (where you work on another team's codebase) is absolutely toxic. Avoid it at ALL COSTS. It will be the worst months of your life as you'll be expected to produce the most perfect code, improve another team's codebase, go oncall for them, and do it all faster while being slowed down by absurd kafkaesque processes On-call can ruin your personal and social life and sleep. You can be expected to work for 16-hours straight after waking up at 4 AM.