Pros
I've worked here for 3 years and am overall very happy. Sure there are things I can complain about (see cons) but this will not be avoided by moving to another employer. Compensation is merit based, which definately encourages people to pursue their passion and actually care about the work that they put out. When something is wrong, people actually listen if you have a better idea, in many cases, if you can fix it, you should and do (and get credit for it). Training is top notch, no other company can teach the complexity of healthcare like Epic does. Your first six months are more valuable than your degree when it comes to actually being a functioning part of a team in a giant healthcare organization. The customers ROCK - no substitutes for this one.
Cons
Besides all the petty and trivial things people have written I would say turnaround can be be tough on everyone, Epic struggles to hold on to some of it's best people because of grad/med/law school. Also, I vomited when I learned what developers make.