Pros
You'll often get along with your team and everyone is generally nice.
The food is pretty good and affordable.
The training is in-depth and sets up a basic framework for your day-to-day.
If you're invested and willing to put in the work, you'll see some nice return for your effort.
Epic has some nice events where you can enjoy some good food and company, and conferences where you can learn more about your industry standard practices to help improve your knowledge and maybe bring back some enhancements to your team.
Exploring the campuses is pretty fun too (if you can find the time).
Cons
Your experience with your TL (manager) is very much a coinflip. There's some chill TLs that will go to bat for you and make the effort to help you improve in a civil way, but then there's some TLs out there that are only concerned with either their career or only care about improving their application in exchange for stretching their team's production thin and giving everyone way too many tasks instead of focusing on more feasible action items and projects in scope.
There's not a company-wide standard to how you're supposed to do your job. Each application/team will do things differently depending on their testing captain or TL, so don't only be relying on your training to get you through the day.
From what I understand as well, Epic uses a lot of internally made tools to assist you in doing your job, but other companies in the industry don't use these tools, so knowledge transferability may be limited if you're looking to start your career at Epic and then move to a different company in an adjacent industry.
Expectations get pretty high, pretty fast due to the nature of the industry (healthcare software), so pressure does mount rather quickly.
If you make a mistake/slip up, there's an internal 3 strikes system, but they don't tell you when you make a mistake in their eyes. After that, you get put on an improvement plan which can be brutal depending on your TL and what they think of you, your work ethic, and the work you bring to the team.
Bonuses and raises for quality managers is usually low.
Sometimes upper management makes very unfavorable changes to your benefits, jobs, or across the company.