Ventajas
Working with truly wonderful, smart, and competent coworkers. Good mission. Walks the "Employees are family" talk with exceptional benefits, such as half days every other Friday, unlimited PTO, and lots of tiny benefits that add up to a lot of love. Most employees like most other employees, which is huge. There is a lot of trust going both ways.
Desventajas
Salaries are lower than you could get elsewhere and the organization runs lean in terms of available hands to solve the many issues. I think it's a good tradeoff in return for which you get stability that's rare in tech; they're slow to hire, slow to promote, but they're slow to fire, and so far I've never seen a layoff.