Pros
Duke Health System is an excellent employer for the right kind of person. As a baseline, Duke is an excellent place to build a resume, has great benefits, and reasonable salaries. Overtime is rare (at least in IT) but be aware there is no compensation if you are salaried for overtime. Duke is truly focused on patient care and it shows - we have high patient satisfaction and management definitely puts (rightly so) a high degree of emphasis on this. It can make working there very rewarding knowing that you are truly helping people.
Cons
To advance, you may need to play a political game. Advancement in the same position can be rare - this means that advancement usually comes in the form of switching from one job to another within Duke. Politics are worse than other places I have worked and it is pretty much a requirement that to advance you must play the game. This can be very frustrating at times and especially to new hires. Another downside is the "dead weight". Job security is fantastic but it works both ways - meaning there are some very incompetent people working (again in IT) who seemingly cannot be fired. At best, they are shuffled to a different position and await retirement. This can make working at Duke difficult when one takes "fairness" into perspective.