Pros
Remnants of old school corporate culture where everyone treats you with respect. Potentiall very friendly atmosphere. Travel opportunities for consultants although some of the places you go to will not be that exotic. Rapid promotion is possible if you are lucky and/or have been identified. Sounds cliche but it really is what you make of it.
Cons
Very impersonal. I have never met my manager in person. Arbitrary promotion and resource deployment scheme within the consulting organization. Project deployments based purely on billable hours, no regard is paid to career growth. Pervasive bean counting. Management shakeups are frequent. Old PriceWaterhouseCooper organization is not well integrated. If you're not one of the lucky ones on the fast track you could be in for a very miserable time as no one is really watching out for you.