Ventajas
Here's the secret to success at Lockheed Martin: stretch assignments. If you come in as a new hire and wait for your lead to get work you ARE average. My mentees regularly complain they get an average rating (we are rated on a true curve) when they think they are knocking it out of the park. You can come in and watch an hour of YouTube and troll Reddit all you like. You will probably even make E3 without much trouble, but you will not get many opportunities. No one cares you had a 4.0 at a top 25 university, we all did. We respect the time you served your country, but you have to keep working for us, too. At Lockheed you don't even have to work overtime to be above average. You have to stretch. Ask for more work when you are close to done. Ask for work in an area you specialize. If you get hired in bonding parts but you did research in optics tell someone! They will respect it and find a position for you! Talk to your managers. Ask them how they got where they are. I guarantee they worked nights, they screwed things up, they made mistakes, but it was because they were paving the road through hard work and innovation. If you make a mistake here, it is ok. Learn from it and don't let it stop you.
Desventajas
Nothing will be given to you. The "rack and stack" (curve-based rating system) means that management can't hand-hold everyone without damaging other peoples' ratings. It can seem opaque at times, but if you ask someone that was rated above you what they did for the year, after they finish explaining it will put you in your place. Due to the size of the company your cube-mate may be working a project on the side you have no clue about.