Pros
MIT can be a fantastic place to work. The culture is exciting, the faculty and students are all excited to be there, and they make the job fun. The benefits are great, there are ample opportunities for career development, and as long as you are willing to move between departments, lots of opportunities for advancement.
Cons
Like many jobs, a lot depends on luck and politics. Some faculty forget that administration is on their side, and it's not unheard of for administrative and support staff to get treated with very little respect. This can usually be remedied by changing departments, because this isn't a majority of the faculty. However, the faculty are the priority, so seeking help to improve a current position doesn't seem to help when the conflict is with a member of the faculty.