Pros
I would repeat previous comments made by others: Excellent compensation and benefits. Competitive fully vested matching 401K. Lots of work with in some really great organizations. Partnered with very strong companies in a growing sector, Cybersecurity. Small, but growing company with strong plans to grow and continues to seek out and is moving to secure ever more work throughout Northern Virginia and Metro DC, along with many other areas of the country. Leadership is very attentive to employees work/life balance, among the best, a truly remarkable subordinate company!
Cons
Being a subordinate company has many downsides for a contractor. Communication, competing interests between the customer and your other customer the Prime, low overhead means just that, very small company support footprint, be prepared to stay on top of your employment back office needs, small growing companies have small offices where one or two persons wear many hats and can't always do everything like a large company can for your professional and personal development.