Pros: work/life balance, retirement benefits
Cons: not the best place for new employees fresh out of college
MITRE is a good employer - Market rate compensation, good retirement benefits, good work/life balance, great job security...but it's not a *great* place to work.
The culture very much depends on where you work in the company, both in geographic location as well as specific department, but in general things just happen slower than they would at a for-profit company. Middle management and executive leadership rarely seem to mesh in message.
Many have said "MITRE is a great place to retire," which seems accurate.