Pros
Intellectually challenging, get to work with different companies in different industries, be part of a team, set career path for promotions, great benefits,
Cons
It's great to start off your career but in order to stay long term you have to be willing to give up any control you have over your time whatsoever. Doesn't matter how quickly you get your work done, you won't be able to go home at a normal hour. For some employees the hours are better in the summer but you can also be put on an engagement with a summer year-end which means your busy season can last for most of the year- which equates to 55-95 hour work weeks. It's just not healthy to have to sit at a computer for that many hours a day for 6+ months out of the year. Also gets in the way of time with family, having a social life, love life, etc. Also some offices have a lot of politics and favoritism is given to people with the right connections.