Pros
It's an exciting environment, and you get to do something fun. It's hard to write a true review for MIT since it depends on the office your in, but I can't imagine any office which wouldn't support freedom of thought. The location is also quite good being right at the edge of Boston. Many shows which travel to the East coast make it to the Boston area. The MIT Student Center also has a great arcade with some of the most popular games. It makes it possible to stay there even when not working, just for fun. All the people are really nice as well.
Kontras
There's lots of variance. Some departments have free food and drinks, while others just coffee and tea. The area around MIT isn't the best. Kendall square has a few okay places but for the most part it's an industrial complex. The lunches aren't horrible but there are probably better places around. MIT itself is also a confusing place. It will probably take a while to get acquainted with the layout. For one, all the buildings are numbered which means if you like names, you're going to be out of luck. Furthermore, the numbers aren't consecutive, so that might be tricky as well. There's a system but it's not immediately obvious.