Pros
RMS appreciates hardworking individuals, and recognizes high-value contributors with rapid responsibility growth and promotions. The chief engineers I had the privilege of working with there were exceedingly competent in both technical aspects of their programs and the politics of funding. On a personal level, it is very fulfilling to contribute to the safety of our nation's warfighters.
Cons
The "matrix organization" of RMS (program vs department) results in a behemoth monster where the left hand has no idea what the right hand is doing. This results in a yearly promotion system where you are ranked by people who barely know what you look like against peers that work on different programs, in different buildings, on the other side of town. So, if you are hired by a misogynist who thinks you are a "risk" then you should be prepared for a lifetime of making significantly less money than your peers, even if your program thinks you are an amazing engineer.