Pros
I have been a MITRE employee for over ten years and I can tell you first hand its not as bad as these reviews make it seem. Going into a tough economic time they decided to cut free food and make coffee free for a company over 10,000 people which I think is exactly what a responsible steward of government money should do. During the pandemic we were gainfully employed, sent to WFH for our safety, and the corporate operations team bent over backwards to ensure that IT and other key functions never missed a step on a shoe string budget. Recently the organization made a benefit cut that only impacted staff with over 9 years of service, but in turn they rewarded the other 65% of the staff an additional day off. They did not go after retirement or healthcare like some other organizations have done lately. Working here you get to interact with some smart people, and work on real problems. We have 12 weeks of paid parental leave, and they will let you go and get a masters or PHD with an incredibly (often close to 100%) reimbursement. Its not perfect, but its no where near as bad as some of these reviews make it sound.
Cons
The move to the gov fiscal year to the calendar year has felt like chaos. Company has a lot of VP's and can sometimes feel top heavy at the VP/SVP/C-Level.