Pros
The opportunity to work on large clients who will only deal with the big firms who are usually household names. The clout of the firm means that for some sectors the competition is purely between the large firms regardless of the size of the team required to actually carry out the work. Perception is everything in this case. There are opportunities to work overseas and still be employed by the home practice. The size of the organisation means that their is a good library of information to refer to and a lot of industry specific knowledge in very niche sectors.
Cons
The management and communication within my department is astoundingly bad. Opportunities for new work are missed and the department seems to obtain and keep clients despite the team's best efforts to lose them through incompetence and mismanagement. There is too great an emphasis on paper pushing project management with the time spent on actual useful work for clients suffering as a consequence. There also seems to be great emphasis on producing thick and heavy reports which actually have very little content or original thought. The EY name added to a telephone directory would probably suffice instead. Recruitment processes seem to take a long time resulting in failure to provide resources in times of need and then a glut when there is less work.