Pros
You are given the opportunity to work with interesting clients, and the teams are all very hard working and intelligent. Benefits are good overall. Office culture varies greatly from city to city, there are a lot of remote workers too. Opportunity for promotion is limited and highly dependent on which team you're working in.
Cons
I am often assigned to work with clients and teams outside my time zone which can have a strong negative impact on work-life balance. Workload can ramp up very suddenly and leave you in an extremely high stress situation. Management attempts to support, but it doesn't always result in much relief. Internal politics can be very challenging, there is a lot of fragmentation between internal teams, largely due to the acquisition driven growth model.