Pros
Great mission. Huge name/role in the international scientific community. Very capable colleagues.
Cons
People are worked to the bone with no clear path to promotion or pay increases. Dreadful compensation for anyone sub-senior level, and the perks don't make up for it. Highly intelligent and devoted staff are undervalued, especially considering the organization's role in the world of scientific research (Science is a source for about half of the science stories in mainstream media and the journal of record on Nobel Prize-winning research). The justification is they're a nonprofit and their brand recognition leads to superior opportunities, which isn't wrong. Too bad those opportunities only exist elsewhere. Diversity is a mixed bag—staff represent all kinds of ethnic and geographical backgrounds with solid gender parity; however, you won't find many ordinary people who believe quality of life goes hand in hand with income and job security. Perhaps that comes with the territory in a space closely aligned with academia.