Great place to work, if you like the quasi-government feel
Pros
Good with DEI, good work-life balance, nice facilities, good food options, decent benefits, lots of interesting projects and technical exchanges in-house, lots of very smart people. During good times, internal money is available for creative projects. During good times, there is internal money to carry an employee for weeks between preojects. Most of the time, there is not a lot of deadline pressure nor a need for a lot of overtime. Your work is contributing to a stronger or better US government.
Cons
Projects end based on government sponsor whims and then the employee (except for newer employees) has to essentially conduct an internal job hunt. If you like product development, MITRE doesn't do that, though MITRE does develop prototypes. If you are shy, it is a bit challenging to move up since there is growing expectation that you will lead or present. Base salary is not as high as some peers.