Still learning MITRE, but good experience so far
Pros
--Great work-life balance (they really mean stick to 40 hrs or close to it) --Great benefits--25 days combined PTO that you can roll over and cash out within certain constraints; health etc; great retirement matching --Collegial/collaborative culture --Strong commitment to professional development (I'm learning how that works) --Strong commitment to the public mission--they really want to help government work better
Cons
--Like any place, there can be a mix of calibre of professional (and some surprising promotions, as a result) --Not exactly a con but a complexity: MITRE in fact is a corporation that hosts multiple FFRDCs (federally-funded research and development centers), and the different centers appear to have different personalities. At least in the center I'm in, there's a "matrix" thing going on with folks in mission groups who are dedicated to understanding a client and client mission very well, and other folks in practice groups who bring specialized practitioner expertise to client engagements. My center is still working on how the mission and practice groups work together.