Long lines but very smooth and easy. American CO switched over to English with me as I attended the interview with my fiance and I answered the questions, did not seem very comfortable with her Spanish. They returned my original divorce decree as it was the only certified copy I had and I was able to leave a copy with them (but only because I requested so). Very smooth and easy. A little confused at first as K1 isn't technically an immigrant visa but we were put in the immigrant visa line outside the building.