Pros
The company has a very flat hierarchy, the team structure on accounts is very much like working a free lance environment. You are very much responsible for your own time. The roles of people tend to evolve organically out their specific interests related to their discipline which can be very powerful with a highly proactive group of people together on one team. The atmosphere is very causal and relaxed no hard hours, you are just expected to get your work done on time and on scope.
Cons
The lack of structure can also be a weakness if a group comes together where no one champions the project and if individuals responsible for their discipline do not own their work. We also seem to have staffing issues, we can never seem to fully staff and account. There are also issues regarding properly scoping and scheduling projects, rarely is appropriate amounts of time given to programming, although I've seen improvements as of late.