Ventajas
Lockheed is one of those companies that realizes its bottom line is directly related to its greatest asset: the people. Besides offering numerous opportunities/avenues for vertical and lateral movement, they also invest heavily in L&D (Learning & Development). They are extremely diligent in recognizing/rewarding excellent performance. And their commitment to diversity is second to none in my book. The only possible obstacle to professional (and personal) growth at Lockheed Martin is yourself!
Desventajas
As a government contractor, the emphasis of dotting all i's and crossing all t's three times over is a bit overbearing. I had to keep track of my time in no less than FOUR different tools. It got to be a real drag. Also, LM's performance evaluation system is extremely rigorous, time-consuming, and tedious. If strict protocol is not your thing, government contracting may not be for you.