Pros
The food is amazing, the campus is nice (although traffic and parking is a nightmare). The pay is decent and apparently it is increasing. The benefits are very good. Epic has a huge share of the market and honestly has the best product out there. They aren't going anywhere and your job should be safe for as long as you want it. They are desperate for developers.
Cons
HR does not tell the truth about what you will actually be doing. Depending on what team you get placed on, the code ranges from slightly broken to profoundly broken. You will almost certainly not work with .NET. You will work with Cache (also known as MUMPS) and VB6. These are old, unsexy languages that struggle to work with modern technologies. Epic works around these limitations by being "clever" (which should set off warning bells like a depressurizing submarine). Most of their tools are homegrown or obsolete because no one supports Cache and VB6 anymore. It's possible to work 40 hour weeks by not volunteering for anything. You will work on the most boring bug fixes that they have. If you volunteer for anything your workload will increase to the 50-60 hr/week zone, trying to integrate new development into the incredibly finicky and interconnected codebase. Basically, a boring, frustrating job with questionable management and the potential for major overwork. They have a massive backlog of bugs that need to be addressed as they slowly begin to modernize their code.