Pros
Relaxed work environment, long lunch breaks with lots of chatting. Self-managed and therefore ability to work as you like. Cheap cafeteria.
Cons
The management and the HR don' t apply and respect the company rules and procedures. People start grievances against their managers or colleagues. Dishonest and unhelpful co-workers (the ones that have lasted many years know the tricks and how to set traps). Beware of those "very friendly and polite" faces, they might stab you in the back. Many business and employment decisions based on personal political agendas. There is so much overlap in roles, some managers are doing almost nothing. Management clique is made up mostly of outdated people that have outlived the company. They know the company rules and how to break them without being caught.