Pros
Widespread open-mindedness. People tend to be very flexible with understanding and accepting new requirements, expectations, deadlines, or initiatives. Young-spirited environment. People are ready to evolve with the business. Meetings can be very informal which aids in brainstorming and general creativity. Empowerment. My experience with my managers have been very empowering. They grant me autonomy to handle my tasks and allow the quality of my work to speak for itself. If you put in the time and effort, you are rewarded with more opportunity and responsibility which is what you need to advance in your career. In house support Our development and support team is not a third party resource. They're there when you need them. Work/life balance My experience is that we take work/life balance very seriously here. Yes, there is tons of work, but that doesn't mean you can't go home after 9 hours in the office and recharge for the next day. Working from home is often an option for those that don't have in house meetings. Don't forget the free healthy food.
Cons
The fast-paced environment can be a lot for some. You will always have more work than you can do in a day. However, as long as expectations are managed, it is not chaotic or overwhelming. Communication between departments is sometimes lacking and with a fast paced environment, things sometimes change without others being aware of it. It can be a challenge to get everyone up to seed.