Pros
Talented coworkers, good projects, opportunity (not guarantee) to learn a lot quickly compared to other offices. Good place for a young person who knows what they're getting in to (and plan to get out in 2-4 years).
Cons
Unlike self image, the social culture is very cold and impersonal. Everyone is replaceable yet competing for fleeting and insubstantial approval. Self destructive partner behavior. Partner inattention to projects in documentation phases and construction. Bizarrely still extremely focused on bringing in development work. Inability to retain experienced staff, low pay. High turnover in last 1.5 years, hemorrhaging experienced staff and no sign of change. No functional HR, little attention to individuals goals or problems and little self reflection. Self destructive working culture where long hours are encouraged/expected and rarely rewarded. Damaging culture for personal or family life.