Ventajas
You may get the opportunity to work with some of the most brilliant engineers. I enjoyed learning from them and working with them. It is solely what made it hard to leave RSA ultimately.
Desventajas
RSA is a good fit for those who are winding down their career and would like a stable, non stressful environment to work in. This is reflected in a large percentage of the employees. This can be frustrating if you are still trying to grow in your career as there will be massive opposition to change on almost every team and at the highest level of management.
If you are hungry for growth (personal, professional, financial), this is not the place for you.
Despite several attempts with providing real life data on how severely underpaid employees were, management was not open to benefit/salary adjustments. It was standard for an employee (regardless of what team) to get an offer that is at least 30% higher from other companies after taking a single interview.
(If you are interested in a company that recognizes the need for DEI, RSA is not the place for you either.)