Pros
There is wonderful camaraderie among the staff. Colleagues are supportive of each other and develop close friendships. The mission of the organisation is morally admirable and everyone who works there believes in it. There is the opportunity to be creative and flexible in terms of coming up with ideas for projects: a colleague once described it as 'choose your own adventure'. The work is constantly changing and stays interesting. There's an excellent benefits package, flexible working, and lots of fun perks including career development opportunities (in terms of broadening experience, rather than rising up the ranks).
Cons
Some colleagues get burnt out and overwhelmed from the workload. Compensation is on the low side because it is public sector, and there is little opportunity for most staff to progress past a certain level.