Small company = no bureaucracy and lots of flexibility. You work things out with your manager like adults. The people are friendly and professional. Work/life balance is important to everyone, including senior management.
Minpunten
The small size of the company means that unless you're a customer service agent, there won't be many other people doing the same thing as you. This can limit opportunities for learning. You'll need to be self-motivated if you want to develop.
Decent people in the mixture
Middle management has brain cells
The product is fun to work on
Minpunten
Upper management/Chiefs don't have many brain cells
Has a culture that believes you can never score a 5/5
Very niche product and hard to translate to other areas in the same field