Pros
I worked here (Space Park, Redondo Beach) for most of 1995 to 2017 (originally it was TRW, bought by Northrop Grumman in 2002). To this day, I still think the benefits are very good; there are many choices for medical, everything from premium PPOs to HMOs to opting out entirely (which some people do if their significant other has better benefits through another employer). Sure, it's probably not as generous as it was back in the 1990s, but where is that true today? Also, management always treated me pretty well, and there was always some emphasis on life/work balance - some people took that more seriously than others, but if you weren't obsessed with rapidly shooting up the corporate ladder, it was always acceptable to have other priorities besides just work. And with a company this size, there were a lot of different opportunities, so I never got stuck in the exact same role for years on end.
Cons
I was in satellites, and ever since Northrop bought the company in 2002, I've noticed a slow decline in the space side of the business (in favor of the much larger aircraft side). There are many more opportunities in aircraft these days, and I started to get the sense that corporate management wasn't all that interested in winning a lot of new space business anymore (just not nearly as much $$$ to be made as there is in military aircraft). So if you're interested in the space side of things, opportunities here seem to be much more limited than they were 12-20 years ago.