Chicago interview
Did mine in Chicago on the 22nd last month. First I was asked swear under oath that you're telling the truth and nothing but the truth, and then came a quick firestorm of questions about things in my application. The whole thing was mostly painless. Because I'm a college student who goes to school out of state, they asked me to show them my state ID or driver's licence, and I gave them my licence from my home state with an explanation of my situation, and showed them my proof of enrollment and current class schedule from my school.
I have known Mr. Khanna and his team for over 15 years now, and have exclusively used their services any time there has been an immigration related need personally or for my organization. They just have a knack for getting things done and I will unequivocally recommend their services to anyone.