Pros
As a member of a small team, we are all able to have a huge impact on a really cool project plus contribute to a great mission to connect the world. I have learned about many aspects of fields outside of my specialty in mechanical engineering because we are so small and work together all the time, and it is enriching and interesting to broaden my knowledge base into some parts of RF, electrical engineering, software and thermal. The group of employees is very likeable and inclusive as well as smart, and since one of the perks is having free lunches, we have a built in time during the day to socialize. I have found it to be a good balance of people finding friends and being included at work without the requirement that you do external social events to feel like a real part of the company. For a startup, I think that the work life balance is quite good, and while I spend 50-60 hours working per week instead of 40, I think it is time well spent.
Cons
If you prefer shorter, less meaningful work, this is not the place for you. There are some growing pains of being small where we have been trying to build new systems for documentation and planning, sometimes this can be annoying to deal with when things change.