Pros
There is no glass ceiling. Diversity is encouraged. Excellence is rewarded. While some areas of the company have obvious requirements for a specific role (you should have a law degree to be a lawyer) you can move very far simply by being a motivated, business-savvy person. General quality of life is very good.
Cons
Everyone is really friendly and teams intermingle. It can lead to or at least give the appearance of nepotism. If you know the right person and you've developed a relationship with them and they are able to help you move up, how is that any different than networking. I don't think unqualified people are moving up. But I do feel it impacts the decisions when you are deciding which of a couple people you're going to take a chance on.