Pros
Good work-life balance and generally fun, younger staff, especially in the larger offices. Your experience completely depends on your manager and program. I had some of the best managers and some of the worst. There is no management training for new managers and there are a lot managers managing a lot of people who are not effective managers.
Cons
Extreme lack of transparency into human resources, promotions, compensation, and the organization overall. Everything is driven by money. They will do anything for a dollar even compromise project goals. If you do not have money for something new that you want to do then you will not make it past the first conversation with your boss and no one will help you find the money even though there is an entire department dedicated to finding and securing funding for projects. They pride themselves on being "entrepreneurial" which may have been true 20-30 years ago but not any more. This organization operates/acts more like a corporation than a nonprofit. Not the place for someone who wants to do something very different and is very idealogical/passionate. The wasting of resources, time/money, is also unbelievable...extravagant meals, events, salaries, offices, etc. They discuss "diversity" like white ivory-leaguers, they discuss it but do not do anything about it...by far the least diverse (ethnically, economically, socially, experientially) organization I have ever seen or been a part of in my career.