Pros
The company is very stable -- it's not going out of business anytime soon. Layoffs are relatively rare, compared to other companies in the industry. Everyone who works there is at the top of their field, and very easy to get along with. The employees are all genuinely wonderful people, and set the bar high for job performance. Culturally, the company is very thorough. There's a heavy emphasis on process and procedure, so projects are often run very efficiently. It's an extremely comfortable environment; from the benefits to the furniture, it's all rather posh. At times, I've heard the company called "the guilded cage" or "the golden handcuffs."
Cons
It's a very risk-reluctant company, which can be both a good thing and a bad thing. On one hand, the risk aversion keeps the company very stable; but on the other hand, it can be difficult to try anything new. Change comes slowly. Nobody questions The Chairman of the Board. Fair enough; it's his company, after all, and he's the one paying for everything. But there are times when his decisions are, well, difficult to understand; and everyone just has to go along as though it all makes sense. There is not a lot of emphasis placed on personal initiative. There's not much interest in trying something new or taking a risk.