Pros
I spent nearly 8 years at Ocean Science Trust, and for a small non-profit organization, I was amazed at how much impact we were able to have. My field of expertise is in linking science with decision-making on ocean and coastal management and policy issues. Across the many projects I worked on, I and my team mates essentially defined not only what that meant, but how to do it. This is something I have taken beyond Ocean Science Trust to new employers that are frankly far more well-resourced. I will always greatly value my time at Ocean Science Trust, it challenged me in every way and I am much better as a professional for it.
Cons
Ocean Science Trust is a small non-profit based in the Bay Area, thus the pay just can't keep up. Ocean Science Trust does what it can, but it can only do so much. Also, because it's small, formal promotions can be difficult. That said, you are exposed to experiences that more hierarchical places might deny to lower level staff. Finally, if you want perks - like ability to travel to conferences, a more formal/fancier office. That is not Ocean Science Trust. Again, it is a small non-profit in the truest sense.