Pros
Lockheed Martin tries to maintain focus on what is important, overall program success. The company does a good job of decimating information down to the employees. The company has a good life work balance atmosphere. Paid time off is usually granted, unless there is a contract delivery impact. Career growth is very possible due to the large size of the company so long as you are willing to relocate, otherwise it becomes tougher.
Cons
Over the past decade or so, benefits have been eroding . For instance, the out of pocket cost for medical has risen dramatically. Since the company works so closely with the federal government, they have a tendency to become bureaucratic unnecessarily. The company's loyalty to its employees will be sacrificed for the betterment of the company. The pay is on the low end of average end of the pay scale, Not bad enough to make you seriously want to leave, but not good enough to make you not consider leaving. Management focuses too much on yearly compliance training as a performance metric. I have seen employees get dinged on their performance evaluation because they were not timely in completing their training.