Pros
Opportunity to grow in an environment with a culture of high quality.
Big clients.
Good environment with colleagues, although some managers are simply detestable.
Cons
Long hours of work (10 hours a day is normal).
Very focused on the business and very little on the technology: the management folks are clearly favored over the techie guys and projects are not that exciting, technologically speaking.
Very poor planning and lack of basic tools: version control systems, project life cycling control systems, etc