Pros
Great benefits, above average but not highly competitive salaries, diverse and interesting work, smart motivated colleagues (for the most part), and a genuine interest in career pipelines for interns and young professionals.
Cons
Career limitations for senior staff, ALOT of nepotism and "old boy /girl" networks, constantly changing priorities, waivering management commitment to employee driven pro bono work (eg Ukraine project which seemingly evaporated without warning or rationale), limited opportunities for professional growth outside of MITRE sponsored classes, a billing system which thwarts all creative thinking time, Likes to be a place for everyone, which is unrealistic in an "eat-what-you-kill" system. HR system that is completely broken in EVERY respect. All talk, no action.