Pros
The company is on a mission to change an industry and redefine the way we look at health and wellness. Still small and nifty with less bureaucracy and tight definitions around job duties or even titles. This gives the "go getters" so much bandwidth to stretch and grow, going into areas they are very good at or passionate about. You get to take on a broad area and shape that area as you like as long as it meets the company's strategic goals. Superb environment for people who are tired of big company politics, rules, waiting forever to get promoted or explore new areas. If you know what you want from your career you have the people here who can help you. The opportunities are endless and the flexibility is high. Good way to sum up about the company: this is a place for those who have this attitude: the world is your oyster :-)!
Cons
As a fast growing startup, you always need more people and more resources to all the things you want to get done. It takes a while to realize this. Lately, this is recognized faster and resource allocation has been better. A good number of employees are junior (but striving), and need some skills development (which the management is now focusing more and more), feedback loop could be stronger resulting in faster change, adaptation, and iteration.