Pros
Great organization, doing amazing and important work; great benefits (much better than most for profits); lots of time off, including maternity and paternity leave; (mostly) flexible scheduling; (mostly) supportive and encouraging work environment; working with incredibly smart, yet humble, people; focus on diversity; and have a great world view.
Cons
There can be a disconnect between the state chapters and the organization headquarters; communications are sometimes lacking; growth opportunities at the state level are also lacking, especially for low to mid-level professionals (basically due to lack of growth overall) and it can be difficult to break into the employment ops at headquarters; occasional layoffs still happening due to slow return from recession; not a place for people who do not like change--priorities and messaging change often; like most nonprofits, salaries are lower and merit increases and raises can be hard to achieve; should be more of an effort to "walk the green talk"