Ventajas
Lockheed Martin Information Systems has a lot of contracts across the United States, with a lot of Federal and state agencies. So Lockheed Martin Information Systems is almost always hiring somewhere, at some time. They are a known "brand" so they might look good on your resume, and the job title they give you might even impress someone who doesn't know any better. But the best reason to work for Lockheed Martin Information Systems is the deep feeling of joy and satisfaction when you quit for a job that isn't sucking all the joy out of your life. Your opinion might vary.
Desventajas
Oh, let me tell the ways I hated, hated, hated working there. I had a fairly decent job working for another Federal contractor with good wages and respectable raises annually. Lockheed Martin Information Systems came in with a "low ball" bid and won out over the good company that had that contract but to fulfill the contract for the rates they bid, they fired half the incumbent staff (and the firings seemed to be of everyone earning more), and dragged in inexperienced temps to take over from staff who had been doing the job for years. They hired people at one salary and then announced a lower salary on the first day. They were very closed mouth about how much new hires would be paying for health care, so the salary you negotiated in good faith was suddenly about 75% of that amount, with the rest going to pay for insurance. There's no paid family leave--my husband was in a coma but I had to come in and work every day because we wouldn't have had an income, otherwise. Oh, and the white men were routinely paid more than minorities and women.