Vantaggi
Being a startup it gives you the opportunity and authority to build your department and program the way you think is best. You have a great deal of autonomy, responsibility, and expectations, but leadership is very supportive and engaging. They don't criticize you, or micromanage you. The C-suite is very engaged and transparent with the whole company. Everyone knows what is going on, what the main mission goal is, and how they can contribute to make it successful. Any blockers are met with teamwork on identifying the best route to remove them. Individuals are encouraged to contribute in any way possible to make the company a success and good environment to work in.
Svantaggi
If you have never worked at a startup it can feel daunting. Some people like it, some don't. You will have a lot of responsibility and be expected to able to operate autonomously for the most part. If that is not your work style you might not enjoy it.