Pros
The Opportunity - As someone who values the excitement and sense of fulfillment you can only get from working at great early-stage startups, this is one of the most rare and special opportunities I've been a part of.
The Vision - The vision is the kind of vision that feels both big-time and practical, something that rarely comes around. The entire company has a sense that this solution can really go the distance. That is something that makes it easy to stay motivated and work hard, and not something most startups have.
The team - The team is full of not only brilliant, but also kind people, who respect each other, and operate as a team.
The CEO - The CEO has everything you hope for in a CEO... he has a big vision but with in the realm of reality, cares about people, keeps everyone aligned and moving in the same direction, challenging but listens, great fundraiser, eager to learn, can delegate but remains involved in each area of the business, and is a great seller.
Cons
Honestly, No cons to date. Truly love it here and thrilled for the future!