Ventajas
Many employment opportunities for recent college grads. Lockheed Martin is a large company with many projects and locations; there is usually something that will interest you. Decent pay and benefits and a good tuition reimbursement program.
Desventajas
Management positions are plentiful, high paying, and stable, but ultimately a burden to the company and projects. Schedules and budgets are often overly aggressive and with a lack of engineers and decent tools (software and hardware). The company is obsessed with earned value management practices and program schedules / statistics since this is their foundation for bidding on new contracts - engineers are at the mercy of a race to be the cheapest. Strongly encouraged overtime due to a shortage of engineers.