Ventajas
Meaningful work, intelligent yet humble coworkers, ample training, good communication from management and executive team, fair compensation and benefits, generous vacation (roll up to 300hr a year) and sick time (40 hrs), great work-life balance, 9/80's a super plus!! I went into work everyday knowing that I was part of something bigger than me. I had the opportunity to watch C130s being built! :) Executives were present and spoke to ALL employees. My group was the best working relationship I've had in my career. They were knowledgeable, supportive and genuinely wanted to help you move up the ranks. LM also did a great job of recognizing high performers and has programs to help you develop your career as well as gain an MBA.
Desventajas
Very political and your salary grade means everything. It's very hard to move up regardless of performance, as people with seniority (5+ years) outrank you. Be prepared to stay in your position 3+ years (if you're lucky). Also, they have many more strides to take towards a diverse and inclusive company. I am a female-minority and it was very disappointing. They can also improve their benefits. The company I moved on to (another Defense) offered much better pay (40%+), retirement and health insurance.