Pros
Access to state-of-the-art tooling/resources and methodologies to test new technologies before they're broadly accessible to the field. Extremely smart coworkers, great facilities, fantastic benefits and pay. Meta branding can add to the resume if you're on a team with real impact.
Cons
Review culture is horrible. Performance pressure is constant, and expectations can be crushing depending on the team you join. Success here is highly political, you need a good manager and good relationships with higher-ups in your org. Post-2022, everyone is scared of being laid off and the anxiety + depression is toxic and contagious. There's high churn, and there's a lot of performative signaling to gain favor and stay in the game longer. Depending on your team, you may not work on anything interesting or high-impact. Take a job here if you're willing to work hard for a few months/years, but don't let your lifestyle creep up too much from the pay bump -- save aggressively in case of long-term unemployment if a re-org impacts you.