Pros
CGD is an intimate think tank, punching above its weight in terms of policy impact. Working there is an on-going education in development with access to constant, rich intellectual stimulation. Virtually all staff are supremely qualified, outwardly friendly, and authentically dedicated to making the world a better place. I have a deep admiration for CGD.
Cons
Because everyone is so smart, everyone feels pressure to prove it, which undermines collaboration. While collegiality in a strictly professional, polite sense is high, the psychological safety that allows organizations to efficiently harness collective intelligence is low. That is, good ideas from anxious junior staff (even senior staff) frequently go unsaid. Like most think tanks, CGD rarely can accommodate entire careers, little room for advancement among junior staff. Senior staff can be a little rigid, but I imagine this is common among think tanks.