Avantages
The defense industry seems to be fairing better than others right now (can't outsource defense, right?) Raytheon is a pretty flexible employer and doesn't stress about small things (like what hours you work) though sometimes this becomes their fault. There is a company-wide work schedule of working nine hour days to get every other Friday off that many employees take advantage of, though that extra hour can wear you down during the week. My benefits package seems seems to have some perks that other employers don't have (eg., dental, vision) though they've stopped offering the pension plan to new employees. The company is so big it's often easy to move (both up the ladder and geographically) without having to jump employers and lose your seniority.
Inconvénients
I don't think any of these are specific to Raytheon, but rather some disadvantageous of working in a megaCorp; Bonuses/pay increases are pretty much the same for the slackers and the high performers (ie., a slacker might get 2.8% raises, and a high performer may get a 4.3%.) Corporate propaganda is never-ending; each year the leadership develops a new set of buzzwords to push down the ranks and you have to pretend like you like it. Like most jobs (though even more so in Raytheon as senior leadership can't be everywhere at all times) your promotions are tied directly to your immediate supervisor. This can be a positive if you have a good relationship with your supervisor, but it can leave fewer options if you don't. In the end, Raytheon is a big pond; big fish will find opportunities to grow and stretch their fins, but small fish find themselves lost in the weeds.