Vantaggi
Definitely they are the type of company that is willing to train and educate their employees to do their respective jobs. While there are the same typical politics that exist in other organizations, they do seem to be very employee focused and do seem to genuinely care for their employees...at least where I work. They are very open about compensation and publish the salary grades for almost every position in the company (on the internal website) and there is an anonymous message board where pretty much anything and everything seems to get addressed there. Certainly, any administrative support I've needed was dealt with appropriately.
Svantaggi
It is very project focused and knowledge doesn't seem to get propagated across different programs. Of course, as we're all essentially contractors for the government...when the program winds down, we'll all get RIF'd if there's no follow-on work and that's an obvious downside.