Pros
SAIC is a large company; so there is plenty of opportunity for lateral moves if other opportunities present themselves. I have not executed a transfer of this sort myself, but I manage an employee sho has, and his experience indicates that organizations are not hostile to intra-company moves. Opening the company intranet and reviewing the "Careers" page where job opportunities are listed always reveals a considerable list of available positions. Knowing that the company has enough work to solicit employees is a nice comfort, particularly during economically difficult times like now.
Cons
Being a large company can also work against the employee experience as well. For example, there can be a large gap perceived between *senior* senior management and the project-level employee.