Pros
Depending on the department, employees can be congenial. Benefits are generally good. Pay depends on level of employment. Obviously if you're an RN with experience, MD, Manager, the pay is good. Otherwise, it all depends on the area & level of employment.
Cons
Obviously, it's important to be evaluated by a manager/supervisor within your area of expertise. Obviously, tenure in any given area depends on the manager/supervisor. What is not obvious is who is evaluating who; in a large department, it may be that other employees are providing feedback that one does not know about or know that it's happening. Then again, if you've been there a long time and have friends who will give you a great letter of support to your supervisor ... sweet. It's an unlevel playing field, to say the least.