Avantages
CSC are happy to give you as much training as you need, I therefore think it is an excellent place for individuals whose career is in its infancy. The sheer breadth of clients means that you could be working across multiple industries; adding lots of experience to your CV.
Inconvénients
The capability of senior management seems to be a bit hit and miss. However, there are some extremely talented senior managers and if you're lucky to get one of the good ones you can expect your career to grow significantly. The ability to move from one account to the other is not as easy as they make it seem, you sometimes have to jump through hoops to convince them. Finally, the processes and methods you use to manage projects can change from one account to the other depending on what the client dictates.