Pros
Your coworkers will be among the most talented and dedicated coworkers anywhere in federal contracted service. Scheduling flexibility is offered by the company, so long as the federal customer supports it, too.
Cons
The corporate identity sales pitch does not meet with reality. The party line is that the personnel on various contracts communicate across the back channel, resulting in improved efficiency, common practices and shared lessons learned, especially when compared to having contracts awarded to multiple firms. The reality is that internal business units act independently of one another, sometimes competing or working at cross purposes. The story may be closer to true among the sites in the Washington, DC, area but remote sites are more like distant relatives. The company takes an unusually high percentage of the contract billing rate compared to employee compensation, and has been known to change the cash bonus plan without adequate detail in the advanced notice. (The former customer satisfaction bonus plan was converted into budget for modest 401k matching and a "President's Club" travel program which basically appears to be a codified boondoggle for corporate officers. Some changes will be forthcoming, indeed!)