Pros
Will only say about IT department based on my experience. Healthy and professional environment. Satisfactory compensation packages for most employees. Organization pays attention to professional development and education. Company tries to take care of its staff, makes an effort to keep people reasonably happy.
Cons
Professional growth is limited after a certain level due to the company size and due to fact that turn over is low, a good thing generally, but not good for employee growth. Many management positions remain occupied by staff who is there for years and since company size does not grow too much, new management position don't become open easily. Also hiring processes are very slow and the organization spends too much time on hiring on open position. Result is that good management position don't become available and other technical positions are not filled fast enough. Chronic shortage of staff because of slow hiring that forces to work harder.