Pros
MIT has excellent benefits: great health insurance, cheap parking if you're into that sort of thing, and a crazy number of vacation days (20+federal holidays+vacation days). There's an extreme level of job security in a way that's basically unheard of these days. This is an excellent workplace for people who are capable of working super hard for 8 hours a day and then disconnecting and coming back tomorrow. This is a great place to work for people with families or for anyone with serious hobbies outside of work.
Cons
Salary is okay but not great, and raises are going to be about 3%/year no matter how well you do your job. As with all jobs, you sometimes feel like you have extra work to do, but the rewards for doing it are going to be pretty minimal: bonuses aren't a thing here. If you feel like your career is going nowhere, that's because it is; you're a cog in a large bureaucracy. If your co-workers seem like a bunch of burnouts, then the problem might just be that you have unrealistic expectations.