Pros
As GDIT Senior Network Engineer on DOD contracts, you will likely work on cutting edge technology and act as the DOD's subject matter expert. There is little substitute for working with the best technology. GDIT is a company where you can work your way up from an entry-level technician to Engineering or even Senior Management staff positions. Work hard and you can be rewarded in the right environment. GDIT has positions worldwide, so opportunities abound. If you don't like one site/state/country, try another.
Cons
GD bows to any customer depend. Managers that don't work are often promoted out of the work force. Poor ethics/morals are widespread, but this is not GD management specific. The more you see, the more you'll know how messed up the system is. There are extreme levels of management detachment above middle management. These "manager managers" are sometimes so detached from the mission, employee needs, etc., that it seems like it's the worst company to work for at times... but maybe this problem is also industry-wide. Pay is a major problem if you work your way up from entry-level and stay with the company. GD wins DOD contracts because they bid low. They can bid low because they pay low. Once you get to a staff-level position, if GD won't reward you, reward yourself with increased salary by changing companies.