Pros
None. Any pros are drastically outweighed by the cons.
Cons
When they contract you out, they will do literally nothing to help you keep the job they and the other company promises you.
They will also go out of their way to further punish you if you speak out against unfair treatment. They made my life a living Hell.
Nor will they help you find another job if a contract ends, despite them promising they will, and there are spots open for you and your expertise, and the job is publicly listed.
No holidays off, forcing you to work on Federal Holidays, even when no one else is in the office.