Pros
I worked for a long time as a consultant, lots of clients, lots of different companies, lots of personalties, lots of corporate climbing, etc. And eventually turned around one day and decided I wanted a mission I could care about, and a place that was culturally great. Those became my criteria, and WWF has been everything I've wanted. This place is filled with smart and passionate people, and I can go home every night feeling like I'm doing my part to help the world, which overrides much of the daily issues anyone faces in any job. The benefits are outstanding, there is great listening from most quarters of the organization, and the work means something.
Cons
It is a large organization, as such, there is bureaucracy, and a big ship moves slower than a small one. However, positive internal change does happen, and I believe the Senior Management Team wants this to be a great place, and works towards making that happen—it is the best organization I've ever worked for.