Comprehensive but fair, will interview with many current employees, mostly senior management in various locations. I've heard some testing takes place but I wasn't tested, a background investigation as well.
I applied through an employee referral. The process took 7 weeks. I interviewed at Aon (San Antonio, TX) in July 2012
Interview
3 interviews by 3 different middle level managers. Focus on past production and proof of production. No testing or background. Hiring based on past production and past reputation
Interview questions [1]
Question 1
Nothing to unpredictable. Hardest question was reason for leaving.