Many pros, ranging from pay, to people, to benefits. The company is run with integrity by people who know what they are doing.
Cons
As with other small defense contractors, contract flexibility can naturally be limited compared to some other larger ones, but they still do a good job.
Small company, awesome management, no overhead. Higher compensation than working at a large company in the same industry simply because of little to no overhead.
Cons
Depends on your personality, but because it's a small company you obviously can't network as much. Additionally, because of the higher compensation all of your time is spent doing client work. There aren't 'admin' hours or 'training' hours that you may receive at a larger company.