Pros
My direct manager was supportive, engaged and focused on solving problems with the customer. FAI is a huge corporation with a global presence that allows avenues for multiple possibilities when it comes to satisfying a client's request. Lots of dedicated people available to be contacted to help solve a client issue. Friendly people willing to help -- all you have to do is ask.
Cons
Relies more on solving problems through quantity vs. quality. It's hard to find top-notch technical people and the preference is to throw more people at a problem or cycle through mediocre technical staff at a client site. Recruiters tend to promise more than they are authorized to deliver. Make sure you get there promises in writing with the employee agreement before signing. Lots of layers and levels of approval (as you should expect from a large corporation). Lack of community feeling and lack of shared knowledge with other consultants in my expertise. Other than phone calls with my manager, I often felt isolated from the rest of FAI. Trend towards offshoring more and more parts of the organization -- especially technical staff.