Pros
If you are considering joining this team, DO IT. From the interview process to the on-boarding experience to the company culture, this is head and shoulders above any work environment I've ever been a part of. I described it to a friend as 'utopia.' A place where people genuinely care about you, work/life balance is real, and the job itself is interesting and fun. I can't say enough good things about the team and the leadership at this company. My experience here has shown me that it's possible to have a work culture that's empathetic, honest, and people-centric. This is the best place I've worked in my 15 years in the work force and I can't recommend it enough.
Cons
Honestly, can't think of any -- I'm sure there are challenges that any company faces as it's getting ramped up, but they care about you as an employee first and foremost so all other challenges seem insignificant.