Pros
Everyone you work with is great, and works really hard. It's really unique in my professional experience. Management cares, and is thoughtful, and active. There's an incredible sense of all being in it together and working toward a common goal. The Stripe product itself is awesome. The offices are to die for (as is the food). But mostly the biggest pro is that here I feel like I've been given the opportunity to work hard and produce the best work I've ever produced. It's a pretty awesome feeling, at the end of the day.
Cons
Information firehose makes it hard to cope with distraction sometimes. Company is a little bit caught between the company it was (small, plucky, engineer-driven), and the company it's quickly becoming (large, global, diverse). Consensus-building, management-lite style may not be your cup of tea if you're from a more decisive, top-down corporate culture where the power to create forward momentum is centralized in managers' hands. As with any workplace there are communication and cultural imbalances between teams, though I believe people recognize this as a bug when they see it, and work toward improving it.