Pros
Lockheed Martin is strongly placed in the defense marketplace and has mostly weathered the budgetary changes well. The work is exciting and challenging. Opportunities to move within the corporation are there for those willing to do more legwork than a web search. Corporate negotiated discounts are available for employees on everything from cell phone service to vacations. Benefits are better than some, but worse than others. 401(k) match is nice to have.
Cons
Human resources is perhaps the primary reason for 9 out of 10 employees, that I have known, to leave the company. HR is given free reign over salaries and promotions and uses one measuring stick for a technical staff of around 50,000. It simply doesn't work. The processes and requirements are hidden and promotions are based on the feeling of HR rather than the experience provided to them by your direct supervisor. Salaries are low; as is typical for the industry. Benefits are solid but have increased substantially every year for the last 5 either through increased premiums or increased deductibles and decreased coverage.