Pros
The work/life balance at Kaiser is much better than I've seen at other companies. The working hours are earlier than other SoCal companies -- most people are in the office by 7:30 and leave by 4:30 or 5:00. But the good part is that people are not expected to work more than 40 hours a week most weeks. Also, weekend work seems to be rare.
Cons
The organization is a matrix structure so it means that generally, most people have two or more bosses. This leads to a culture of non-accountability and one in which decisions are very, very difficult to make. The culture is extremely consensus-driven and people tend to be passive-aggressive to a fault. This is not the environment where you want to be if you like to get things done. But, if you are happy to coast for a couple of years, it can be a great place to be. People talk about getting 'Kaiserized' if you stay at KP too long: you no longer know how to function in an organization that believes in accountability.