Vantaggi
For the most part, their claim to be data-driven is the truth. The engineers they hire are pretty amazing, and good to work with. When mistakes happen, they blame processes instead of people, and keep iterating on those process to improve them. They follow agile development, more or less. Lower-level managers are supportive. The compensation is quite good, if you work in the states. When you tire of what you're working on, you can switch teams without much disruption.
Svantaggi
Pager duty sucks and, depending on what team you're on, might cause you to lose sleep. It's tough to get promoted, and without a promotion, raises don't always keep up with inflation. The planning process, which determines how much head-count a team will get and what they'll be working on for the next year, feels like shouting into a hurricane, but with documents. While the data-driven thing applies to most people at the company, the CEO and "S-team" (C-suite) seem comfortable backing up their decisions with mushy opinion statements. When a lot of employees voice their opinion that a policy makes them unhappy, upper management responds with a shrug, and lower management is sympathetic but powerless. Like most (all?) corporations, they don't care about you.