Pros
Low stress environment. There is plenty of time to get the work done, and I never have a supervisor breathing down my neck or placing deadlines on me. Other employees are friendly and helpful. There is little to no smoking, drinking, swearing, or crude language in the office or at company events. I almost never stay after hours to complete projects - if you don't get it done today, just work on it again tomorrow. The managers seem stressed and busy, but not the lower employees.
Cons
Departments don't always communicate well with each other, which leads to confusion and contradictory directions. The company is small enough that perks like provided lunches or outings are somewhat rare. Also, day-to-day tasks get monotonous over time (after a year or two).