Pros
Red Hat is an enterprise software vendor unique for its commitment to open source software, employing many experts across foundational technologies. It's incredibly common to meet engineers who are brilliant yet humble, "I work on (the Linux kernel/GNOME/glibc), no big deal" that it's easy to forget that most companies don't have this level of talent. This is frequently because the best engineers are so dedicated to open source that they wouldn't consider working for anyone less committed than Red Hat. Engineers are given wide latitude to work with the community and write high-quality code, even if it takes a long time. Depending on your role and responsibilities, working hours are flexible and remote work is common, which is an ideal situation if you have young children. Associates are encouraged to provide feedback on company-wide mailing lists and the subscription business model leads to predictable revenues and therefore consistent profit-sharing bonuses.
Cons
If you're not in one of the major offices like Raleigh, you can expect to be sidelined to some extent, unless you're in a role that includes travel to HQ regularly. I don't think this is intentional; just the usual "out of sight, out of mind" situation. In many ways, working at Red Hat is like being at a non-profit: strong mission (devotion to open source), less stress than other companies, diverse workforce, but lower compensation than industry peers. The projects that Red Hat initiates are usually poorly-managed and chronically underfunded, so they are usually quietly discontinued after some time. Red Hat works best when contributing to projects that other companies are leading, such as Kubernetes and Docker, but that limits growth opportunities and reduces the value proposition of its products. Despite the talk of transparency and openness, many leaders simply don't want to hear dissenting opinions (hey, it's human nature), so encouraging open dialog often results in employees unknowingly stunting their own career development by speaking out.