Vantaggi
You can't beat the mission of NGA and the value that is sometimes created for users. The pay is great compared to other federal jobs and the benefits are competitive with private industry.
Svantaggi
Be prepared to have your IT break daily. Replies to your emails may or may not ever be answered - some working from home take is seriously, some take it as an opportunity to work part time for full time pay. Are you a good writer? If you are, you will do great because your promotions are based on how well you can inflate you accomplishments. Just remember this if you want to work here: Mediocre performance + great writing = promotion. Excellent performance + average writing = no promotion. Poor performance from leadership is generally tolerated and in the past, even egregious behavior is generally tolerated. I've had bosses who slept with contractors, harassed employees, or got inebriated while on official travel. All of them have maintained their status as senior managers and are still supervising other employees.