Pros
There is a strong sense of community here that is refreshing. Coworkers get together outside of work not because it's "required" but because we enjoy each other's company. Everyone is clear on what they need to do to get the job done. There is not a lot of rules and processes around here but that means that you need to be comfortable with not knowing how best to contribute and being responsible for finding out and working on what's important for the company.
Cons
If you do not thrive in an environment where you have to take the initiative to explore and figure out what needs to be done on a daily basis, you will not enjoy working here. The pay and benefits are not as competitive as well-funded large companies but you get the potential upside of a growing startup.