Pros
They will typically give you as much responsibility as you can prove that you can handle. Great atmosphere for people with work ethic and drive, but not a place where people who have have an overindulgent sense of entitlement. The right people can get a level of responsibility and exposure to very senior leaders at some of the world's largest companies at a pretty young age. For the most part the people you work with will be smart, hard driving and professional. You will have access to all the opportunity and knowledge you could ever dream of, so long as you are not afraid to go out and make it happen for yourself. I loce the opportunities at my fingertips here - the diversity and learning opportunities are second to none. Even if you don't make it to partner, if you can make it a couple of rungs up the ladder here, it will open a lot of other doors for you down the road.
Kontras
Man, the place will work you to death if you let them. Work'/life balance always seems to be an issue, and despite all the grandstanding and internal spin, those who are willing to go to the mat for the company are the ones that end up making it farthest and fastest. Many times, the choice comes down to choosing personal interestes/family vs. work. that stinks. The atmosphere can also be very competitive, especialy on the business consulting side. Those that are looking for a cumbaya culture need not apply. Also, if you expect to be coddled, you might want to find somewhere else to work - Accenture can be a pretty cold place at the end of the day.