Pros
Supportive management and great reputation inside the companies they service. Pay is optimized for the employee and depends on your skill level, the project assignment and client budget. Employees are empowered to manage their projects, and expected to proactively ask for support, if needed. Management excels at providing it, when needed. Also, lots of subject matter experts and highly competent tactical resources in the ranks to assist if needed.
Cons
Doing contract project work does not provide an obvious or traditional career path. It may not be for some people who want or need the grooming, regular management interaction or traditional career path opportunities.