Vantaggi
You'd be hard pressed to find another job where you'll meet such a multitude of people from different backgrounds, races, etc that are your age with a similar career mindset. I also can't think of a job with 5 weeks of vacation for new college grads (who ironically don't have the money to go anywhere with that kind of time).
Svantaggi
Accenture's ability to promote completely mediocre people is truly astounding. They have these claims like "Meritocracy", "Up or Out", and "Best People". To be honest, from everything I've seen, there is a large talent gap between the pre-IPO Management and the lower level managers who will presumably take over. The longer I worked there, the more people I met that I truly respected...and then promptly watched large portions of those people leave. Being on large implementations (Accenture's bread and butter) gives you a strong feeling of being another warm body.