Pros
Access to so many great resources whether it's tools or partnerships with other tier 1 brands. Scale of projects is amazing with a real opportunity to impact so many people and processes. Fantastic benefits and a flexible work environment.
Cons
Constant change including budget freezes and significant departmental re-organizations mean many projects rarely make it to completion. It becomes a game of whack-a-mole where you quickly learn that the single most important thing is managing your internal brand and evangelizing for yourself at every possible opportunity. There is no such thing as "what's best for the company/team". If you are a heads-down, non-self-promoting type of hard worker, you'll quickly burn out. This is a culture that only recognizes extreme extroverts with big mouths and not much substance. Managing-up is virtually all that matters.