Pros
Remote work is a plus, and you (usually) get to keep your computer and office equipment when they inevitably fire you. Most of the employees beneath exec level are wonderful people passionate about making a difference.
Cons
Negligence, incompetence, and indifference radiate from the CEO and COO. The past year has seen five mass layoffs, usually constituting 20% or more of the staff. Between these layoffs, management circulates in and out, with new hires taking the blame for the next round of changes. In the interim, new non-management staff is regularly hired only to be fired weeks later. Our staff of 100+ has been reduced to roughly 30. It's these interim employees that take the heat while management smugly informed us that this is simply how startups work. The last two rounds of terminations happened days apart from each other. After letting the latest head of engineering announce the news of a mass purge to staff and assure us that we had weeks before another, they promptly fired him and cut the staff by half the next week.