Pros
You will get exposure to fortune 500 clients. You will be working with clients that are usually at the top of the organization chart. Typical assignments require that you find solutions to very complex problems. You will have to opportunity to travel and see several major cities in the US.
Cons
The constant travel will wear you down. The review and promotion process is somewhat unfair as typically the managers responsible for your reviews and promotions are not the same managers that are on site with you on your day to day projects. This makes it difficult to represent you in their 'round table' discussions consultants are ranked against each other. These rankings form the basis for promotions and for division of the fixed pie of bonus and merit increase dollars.