Pros
The people are fantastic. Most of them will go out of their way to help you in whatever way they can. They tend to care about your professional development and advancement in the firm (and in your career). The work can also be very interesting if you network with people that do the type of work that interests you.
Cons
There are several distinct challenges at Accenture. First, it can be easy to either feel lost in the staffing process or trapped in a niche. This can be mitigated by aggressive networking. Second, when you are unstaffed, HR will try to force you to join the projects that need warm bodies (aka the bad ones). It is in HR and the firm's interest to maximize your chargeability, but this may not align with your career interests or skill-set. Again, this challenge is best mitigated by aggressive networking. Third, the review process can be challenging given the number of employees involved. Even high performers can be passed over for promotion if they or their reviewers lack the rank or political savvy necessary to lock in a high rating.