Pros
You get to work with the best of the best. Everyone here is genuine, intelligent, and cares about the mission. The CEO is transparent and makes an effort to connect with employees. Some efforts being made around innovation that will keep the company advancing toward its goals over time. Culture is pretty good, fully distributed company means you get to form relationships with global coworkers which isn't common at smaller companies.
Cons
Typical startup growing pains, the company restructures every year and it seems to shift focus frequently. Hopefully grow out of this as the company gets bigger. The pay is way below market for anyone who's not on the leadership team. You will be given the workload that typically comes with a startup but the bureaucratic pay structure of a larger company.