Pros
Huge diverse company. You can move around a lot within one company/sector, or explore other sectors around the world. They will help you fulfill your career dreams, whether that means staying on a technical track, management track, or moving around to different functions. There are so many resources out there...big company resources with a small company feel. Since it's decentralized there is some freedom for how each company is run. Also, the credo is really a part of our daily lives, and people take it seriously. It is easy to feel proud working for a company like J&J, since the products make a difference in many people's lives.
Cons
Due to decentralization, sometimes there isn't enough communication between departments/sectors/companies, so there is an opportunity for more levaraging.