Avantages
This company is good for young engineers recently out of college, as long you get on a project with modern technologies (otherwise, you really are wasting your time/skills). They pay well in the beginning, but one you reach level 3, get out. Management at this company thinks nothing of abusing technical staff to work 60+ hours a week to meet contract deadlines that should never have been agreed to. And once you reach level 4, your peers in the non-military/government world will be making much more than you.
Inconvénients
Very political. Senior technical people got to their positions not because of actual technical skills, but because of politics. A couple that I know run enterprise level Java SOA projects, and they've never written a line of Java code before! A huge wave of older senior managers (who were good) level the company within the last 5 years, and their replacements (VPs and directors) were promoted too far too fast, and are doing a god-awful job. Market share continues to plummet, being lost to smaller more agile companies. And LM has been losing an alarming number of ECP/follow-on contracts, largely due to delivery very low quality products.