Pros
This company is very large and has a large job pool, especially if you are open to relocation. There is a lot of potential for public sector jobs, as long as you can obtain a security clearance. Generous on work-life balance as well as a 'hands-off' approach by managers as long as the work is getting done. The opportunities to excel and gain exposure to new technologies all depends on the client's needs.
Cons
This is a huge organization but is still broken down into silos depending on the account you are on. The managers and staff on each account are many times acquisitions from when the company dept was outsourced to CSC, so their way of thinking is usually the company's, and not CSC's. As a result, the company culture can vary widely among assignments. Internal transfers, however, even with a promotion, do not necessarily bring a satisfying increase as if you went external.