Pros
The vision of the company is something that one can really believe in; it was great to contribute to a cause that felt like you were bettering the world. As a startup, there's the potential for unique and very innovative work.
Cons
Truly incompetent leadership stemming from and especially with the CEO. Top leaders are not skilled business people and there is an intense micromanagement culture from the top person; they refuse to admit when they don't know, to ask for help, or to accept help. This has led to numerous bad decisions, which are covered with exaggerations or blame. You either become a 'yes' person to them or you're fired. Negative view of anyone with less than a masters degree. I understand that this can come with the 'startup' label, needing to sell the idea, but downright falsehoods were toted as truth to employees and investors. There's effort to try to get employees better benefits, which is admirable, but it's undermined by the damage (often physical from repetitive movements) needed to achieve an impossible bottom line. Two people were scared off of filing claims while I was there. The company doesn't care about it's people. Turnover is extremely high.