Pros
The casual work environment is fantastic. Wear what you want, work from home when you want, work the hours that you want (within reason, anyway). I've always had great managers, and their managers (and theirs) typically are always open to listen if I have something to say. Pay is good, though not quite as great as some tech companies in the same area. Benefits are good -- though, again, not great -- and management listens. Last year they took away the company-wide week off between Christmas and New Years. Everyone complained so they reinstated it for this year and beyond.
Cons
Atmosphere seems bureaucracy-free, yet some decisions that could take a day end up taking weeks or months. Like most people, I wish compensation and benefits were a little better (soda and coffee are free, but you have to pay a discounted price for juice and sparkling water).