Pros
Fellow employees are generally very intelligent, ambitious, and invested in the work. For me, work is varied and interesting. Corporate culture emphasizes business ethics and corporate social responsibility (e.g., company is "carbon-neutral"). Internal training is pretty good.
Cons
Been with the company over 10 years. When I started the company was probably just over 1,000 employees and was privately held. Work-life balance was good for consulting, employee benefits were generous, and employee morale was pretty high. Now that company has gone public, it has gone on an ambitious acquisition campaign. With the increase in scale, every business process has become more bureaucratic. Employee benefits have eroded (last year we lost sick days during a transition to paid time off, combining of vacation and sick time). Internal training is pretty good, but the federal-sector side of the company is very stingy with external training or travel to conferences. For managers, utilization goals are still so high that proposals and other business development usually have to be done "on your own time" (beyond the 40-hour work week).