In a nutshell, our experience at the US Embassy in London was utterly painless. My fiancée came prepared and was approved with no hassle whatsoever. The interview itself consisted of a few mundane questions that seemed more like a casual conversation than an interview that would directly impact the rest of our lives. The interviewer asked for zero additional documentation; he just took her fingerprints, had her swear she was telling the truth, and sent her on her way with a promise that he would do everything he could to expedite the return of her passport so she could catch a flight back to the US in a few days.
Our circumstances were about as straightforward as they come, with plenty of documentation of a long-term relationship and absolutely no reason to deny the visa, so your experience may vary.
Consulate / USCIS Member Review #7618
Review on May 19, 2011:
