Pros
As others have said, a free lunch is nice...for a while. Working downtown is cool.
Cons
Owners exude toxicity, dishonesty, and manipulative behavior. Was sad to see such a lack of principled leadership. The few who have been on board for a long time drank the kool aid, but there are many more ex-employees who refused it and didn't last a year. You may have the chance to learn some interesting things about technology, or business. But you will mostly learn how to treat people poorly and how quickly that results in high turnover and a sub-par product. Most of everything that needs to be said has been by others. So the last piece of advice to those who come after us, read between the lines on the positive reviews. They confirm that the overall work environment is unacceptable but then cover it up with "well, it's a startup." Ask yourself, do those 4-5 star reviews ring true? If so enjoy the free lunch!