I worked at ManTech full-time (More than 5 years)
Typical pros of corporate employment - decent benefits, work from home days, leave time, 401k matching.
Typical cons of corporate contracting employment - red tape, contract jobs are only as stable as the contract itself.
I applied through a recruiter. The process took 4+ weeks. I interviewed at ManTech.
I received a phone call from the recruiter 2 weeks after I applied. She then scheduled an interview w manager who just kept talking about the culture, the job, the people. She did not ask me any questions.