Pros
Everyone truly believes the work they do is important, which lends itself to committed, happy employees. If you love working somewhere that gives your work a sense of purpose, this is the place. Work-life balance is amazing, and I've never worked with people who care more about each other. There is no "we" versus "us" in management, making everybody (all the way up to the CEO) incredibly approachable. The company also values and wants their employees to innovate and contribute in any way possible - even if it is outside your job description. This gives you a lot of opportunity to move around and make a difference. This is a great place to work if you like to take on a lot of responsibility and have changing responsibilities. You also have multiple opportunities for professional development. Additionally, working here is just a whole lot of fun. There are always activities going on, and the company loves to celebrate successes. You feel appreciated as an employee.
Cons
Growing pains as the company prepares to grow rapidly. In many areas there is a lack of clarity on career advancement - what you need to do to gain a higher title, etc. However, I did find that this was in function only - the company was open about giving you more responsibility if you asked for it. Some disorganization in teams.