Pros
Being such a large organization, there are many opportunities to move into different fields if one wants to. I have had three or four different jobs, including overseas postings. Deloitte welcomes moving people when there is a good reason and the person wants to. Deloitte treats people fairly and with respect. This is rare in large organizations, but Deloitte gets it done. Deloitte is a principles based organization - they live the principles everyday in the way they operate the business such as selecting clients, employees, promotions, taking on new initiatives etc.
Cons
You wont be a multi multi millionaire - even at the top. The hours can be long and sometimes the work is tedious. But, it doesnt last long as the next challenge is around the corner.