Pros
It's an easy-going atmosphere and the office is quiet. The laid back culture can be both good and bad, as there are extended periods where you sit around waiting to be assigned something to do.
Cons
They have absolutely no concept of how to scope out a technical project. They let business analysts drive "how" instead of "what", and since they are inevitably incapable of doing that, there were hundreds of people sitting around for six months - putting in creatively-written weekly status reports explaining what had been "accomplished", when in fact, everybody was blocked on 100% of their assigned tasks for six months because of a complete and utter lack of leadership. I finally gave up (as I couldn't take going to work and having absolutely nothing to do for months on end) and left.