Pros
Challenging - in a good way. You'll learn a lot if you're doing it right. Great benefits. Large enough organization that you can apply for internal jobs. Some wonderful mentors and managers. It's like a small city - within reach, there are banks, a post office, places to buy food, places inside and outside to sit and eat, free concerts, etc. The Getfit annual exercise program gives you a free T-shirt for signing up, and a way to keep you healthy. You get 3 weeks vacation the first year, 4 every subsequent year, and on special anniversaries (10 years?) you get a fifth week for that year.
Cons
MIT does not train managers well or hold them accountable for abusive behavior. MIT does have management training available, but there are few spots available, and let's be honest - those who really need it don't sign up. There is rarely a ladder up; MIT has almost no talent pipeline. This means for most positions, there's no role above you that you can work toward. If you're really good, you may get a promotion to a better title and a bit more responsibility, but if you want to move up, you need to find a new job outside MIT or apply for a different job within MIT. Also, pay and title at MIT totally depends on the department you apply to. Although MIT claims to have a title and compensation system, it is completely subject to the manager and department. More often than not, two people are doing the same exact job with the same level of experience, and they have wildly different titles and pay.