Pros
You get to work with very smart people. The types of problems you solve have a lot of meaning to the thousands of healthcare workers and the patients they take care of. It isn't unusual for people to say good things as they hear I work at Epic and how much easier their life got after the latest new feature or update. Facilities are very impressive. On site food is great every day and is very cheap; huge variety between several venues. Increasing international a presence and opportunity to break ground in new markets. Lot's of growth opportunities. R&D management is knowledgeable in R&D all the way up to the CEO.
Cons
Not every team has the same experiences as priorities across the company need to be balanced appropriately. There are stretches of time where you may not be working on what you want to be working on - as you'd expect from most established companies. Have to consider government intervention and laws as well as a variety of state/organization governance.