Pros
The people are nice. Close knit group. People know a lot about each other's business-- could be a good thing (teammates stepping in during family emergencies) or a bad thing (nosy people wanting to find out gossip). Work / life balance not bad.
Cons
Much mob mentality, clique-y, you are either in or out, better hope you are in the in-group, or you will be on your way out. Not much personal space, everyone in each other's business. There is pressure to do and say certain things in order to appease the top people. Many colleagues have border-line ADD, hard to focus, distracting in the office. Performance subjective, depending on who happens to be rating you. No clear path of advancement and salary increases never discussed. Be wary of asking for too much as it can be seen as rocking the boat.