Ventajas
There is no lack of job security. The last time we had a "reduction in force", we fired a grand total of 35 people (out of 5000). Most of them were able to challenge the layoff via the union, so very few people lost their jobs. LMCO has a very long-term outlook; our major product at MS2 has been around since the 1970s. One can move around within the company, from department to department. As with most government contractors, LMCO pays overtime on contract work. They also have comp time, which is invaluable. (You work overtime and "bank" it to take later as vacation.)
Desventajas
Bureaucracy, both from the government and from the corporation. There's a distinct lack of recognition for competent, steady people. They prefer high-flying egomaniacs. LMCO also suffers from below industry wage standards. Spend a couple of years here and you will definitely want to shop around to see what you are *really* worth.