Pros
It is a nice thing to possess on your resume - the "union stamp" of the finance profession. Per the Wiki, "None of the Big Four accounting firms is a single firm. Each is a network of firms, owned and managed independently, which have entered into agreements with other member firms in the network to share a common name, brand and quality standards. Each network has established an entity to co-ordinate the activities of the network. In two cases (KPMG and Deloitte Touche Tomatsu), the co-ordinating entity is Swiss, and in two cases (PricewaterhouseCoopers and Ernst & Young) the co-ordinating entity is a UK limited company. Those entities do not themselves practise accountancy, and do not own or control the member firms."
Cons
No career guidance or roadmapping, very poor modeling of leadership behaviors by senior management. Consider Michael Lewis' book Moneyball, and the Wiki article "in which he investigated the dramatic success of Billy Beane and the Oakland A's, a baseball team which won consistently despite not being particularly well-funded by Major League Baseball standards. He noted the influence of baseball thinkers such as Bill James on the Oakland front office, which used their arguments to find underrated baseball players. In contrast to other teams which still considered potential players almost entirely on their physical abilities, such as speed and strength, Beane considered prior performance at the college and high school level. This allowed him to find players whose physical skills might have been ordinary, but were still able to play extraordinarily well on the field. James also argued that certain skills, such as the ability to get on base, were equally valuable as the ability to hit, though most baseball decision makers considered the latter to be of more importance. Beane was thus able to find players who were able to provide high value for bargain prices. Lewis determined that these strategies, among others, allowed the relatively cash-poor A's to often outperform much wealthier teams."