Vantaggi
I love working at Red Hat. Not only has my entire team been incredibly supportive and helpful, they are great at what they do. It's hard to find a people like that without the corresponding egos. My work is both interesting and helping me advance my career. The company has managed to foster passion, innovation, and agility even as it grows. They also place a high value on work life balance, even as they help employees find work they're passionate about.
Svantaggi
The company is spread out all over the world with a lot of people working remotely, so it's not for everyone. There's a lot of collaboration over electronic means and less in person. The tools used for collaboration (IRC, mass email lists on ancient email clients, etc) could be a lot better, but there doesn't seem to be any push to invest in it, despite the productivity gains it would provide. The decentralized nature of the teams can also lead to challenges to working across products.