Pros
Your work will have real and obvious impact. You will work with some really smart and motivated people. You will be challenged to take ownership, not just of programming, but your work end-to-end from understanding the real problem to supporting it once it's in the field. You will work for a transparent company that is willing to share with you where it and you stand. You will be challenged to push yourself, and if you're not, you should say something. You will eat the best lunches you've ever had for unbelievably low prices, not that mediocre stuff the Silicon Valley people dish out for free. You will work in a city that's pretty vibrant but not too crazy.
Cons
You will have to deal with processes because this is still a healthcare company, so you might on occasion find that things move slowly. Work life is flexible but you probably can't show up at the office at 11am! It gets cold. Bundle up!